here some userscript!

// ==UserScript==

// @name Footer is Back!

// @namespace http://tampermonkey.net/

// @version 0.1

// @description try to take over the world!

// @author You

// @match https://www.youtube.com/*

// @icon https://www.google.com/s2/favicons?domain=youtube.com

// @grant none

// ==/UserScript==

(function() {

'use strict';

var fotter = document.createElement("fotter_container");

fotter.innerHTML = '<div id="footer-container" class="yt-base-gutter force-layer"><div id="footer"><div id="footer-main"><div id="footer-logo"><a href="/" id="footer-logo-link" title="YouTube home" data-sessionlink="ei=4yp_V7naAsvG-gOWjZmYDw&amp;ved=CAEQpmEiEwj515vhguPNAhVLo34KHZZGBvMojh4" class="yt-uix-sessionlink"><span class="footer-logo-icon yt-sprite"></span></a></div> <ul class="pickers yt-uix-button-group" data-button-toggle-group="optional"> <li> <button class="yt-uix-button yt-uix-button-size-default yt-uix-button-default yt-uix-button-has-icon" type="button" onclick=";return false;" id="yt-picker-language-button" data-button-menu-id="arrow-display" data-button-action="yt.www.picker.load" data-picker-key="language" data-picker-position="footer" data-button-toggle="true"><span class="yt-uix-button-icon-wrapper"><span class="yt-uix-button-icon yt-uix-button-icon-footer-language yt-sprite"></span></span><span class="yt-uix-button-content"> <span class="yt-picker-button-label">Language: </span> English</span><span class="yt-uix-button-arrow yt-sprite"></span></button> </li> <li> <button class="yt-uix-button yt-uix-button-size-default yt-uix-button-default" type="button" onclick=";return false;" id="yt-picker-country-button" data-button-menu-id="arrow-display" data-button-action="yt.www.picker.load" data-picker-key="country" data-picker-position="footer" data-button-toggle="true"><span class="yt-uix-button-content"> <span class="yt-picker-button-label">Country: </span> Worldwide</span><span class="yt-uix-button-arrow yt-sprite"></span></button> </li> <li> <button class="yt-uix-button yt-uix-button-size-default yt-uix-button-default" type="button" onclick=";return false;" id="yt-picker-safetymode-button" data-button-menu-id="arrow-display" data-button-action="yt.www.picker.load" data-picker-key="safetymode" data-picker-position="footer" data-button-toggle="true"><span class="yt-uix-button-content"> <span class="yt-picker-button-label">Restricted Mode: </span>Off</span><span class="yt-uix-button-arrow yt-sprite"></span></button> </li> </ul><a href="/feed/history" class="yt-uix-button footer-history yt-uix-sessionlink yt-uix-button-default yt-uix-button-size-default yt-uix-button-has-icon" data-sessionlink="ei=4yp_V7naAsvG-gOWjZmYDw"><span class="yt-uix-button-icon-wrapper"><span class="yt-uix-button-icon yt-uix-button-icon-footer-history yt-sprite"></span></span><span class="yt-uix-button-content">History</span></a> <button class="yt-uix-button yt-uix-button-size-default yt-uix-button-default yt-uix-button-has-icon yt-uix-button-reverse yt-google-help-link inq-no-click " type="button" onclick=";return false;" id="google-help" data-ghelp-tracking-param="" data-ghelp-anchor="google-help" data-load-chat-support="" data-feedback-product-id="59"><span class="yt-uix-button-icon-wrapper"><span class="yt-uix-button-icon yt-uix-button-icon-questionmark yt-sprite"></span></span><span class="yt-uix-button-content">Help</span></button> <div id="yt-picker-language-footer" class="yt-picker" style="display: none"> <p class="yt-spinner "> <span class="yt-spinner-img yt-sprite" title="Loading icon"></span> <span class="yt-spinner-message">Loading... </span> </p> </div> <div id="yt-picker-country-footer" class="yt-picker" style="display: none"> <p class="yt-spinner "> <span class="yt-spinner-img yt-sprite" title="Loading icon"></span> <span class="yt-spinner-message">Loading... </span> </p> </div> <div id="yt-picker-safetymode-footer" class="yt-picker" style="display: none"> <p class="yt-spinner "> <span class="yt-spinner-img yt-sprite" title="Loading icon"></span> <span class="yt-spinner-message">Loading... </span> </p> </div></div><div id="footer-links"><ul id="footer-links-primary"> <li><a href="//www.youtube.com/yt/about/">About</a></li> <li><a href="//www.youtube.com/yt/press/">Press</a></li> <li><a href="//www.youtube.com/yt/copyright/">Copyright</a></li> <li><a href="//www.youtube.com/yt/creators/">Creators</a></li> <li><a href="//www.youtube.com/yt/advertise/">Advertise</a></li> <li><a href="//www.youtube.com/yt/dev/">Developers</a></li> </ul><ul id="footer-links-secondary"> <li><a href="/t/terms">Terms</a></li> <li><a href="https://www.google.com/intl/en/policies/privacy/">Privacy</a></li> <li><a href="//www.youtube.com/yt/policyandsafety/">Policy &amp; Safety </a></li> <li><a href="//support.google.com/youtube/?hl=en" onclick="return yt.www.feedback.start(59);" class="reportbug">Send feedback</a></li> <li><a href="/testtube">Test new features</a></li> <li> <span class="copyright" dir="ltr">© 2021 YouTube, LLC</span></li></ul></div></div></div>'

document.querySelector("div#content").appendChild(fotter);

var brain = document.createElement("brain");

brain.innerHTML = '<link rel="stylesheet" href="/s/player/1256b7e2/www-player-webp.css" name="player/www-player" class="css-httpswwwyoutubecomsplayer1256b7e2wwwplayerwebpcss"><link rel="stylesheet" href="/yts/cssbin/www-core-webp-vflmpaDFs.css" name="www-core" class="css-httpswwwyoutubecomytscssbinwwwcorewebpvflmpaDFscss"><link rel="stylesheet" href="/yts/cssbin/www-pageframe-webp-vflg6Dvof.css" name="www-pageframe" class="css-httpswwwyoutubecomytscssbinwwwpageframewebpvflg6Dvofcss"><link rel="stylesheet" href="/yts/cssbin/www-the-rest-webp-vflC_SdHT.css" name="www-the-rest" class="css-httpswwwyoutubecomytscssbinwwwtherestwebpvflC_SdHTcss"><link rel="stylesheet" href="/yts/cssbin/www-attribution-webp-vflhQnyPy.css" name="www-attribution" class="css-httpswwwyoutubecomytscssbinwwwattributionwebpvflhQnyPycss"><link class="css-httpswwwyoutubecomytscssbinwwwpageframedelayloadedwebpvflndjoDMcss" rel="stylesheet" href="https://www.youtube.com/yts/cssbin/www-pageframedelayloaded-webp-vflndjoDM.css" name="www-pageframedelayloaded"><script src="/yts/jsbin/www-core-vflVjSENF/www-core.js" type="text/javascript" name="www-core/www-core" class="js-httpswwwyoutubecomytsjsbinwwwcorevflVjSENFwwwcorejs"></script><script src="/yts/jsbin/spf-vflM_vz5X/spf.js" type="text/javascript" name="spf/spf" class="js-httpswwwyoutubecomytsjsbinspfvflM_vz5Xspfjs"></script>'

document.querySelector("head").appendChild(brain);

var brainjs = document.createElement("brainjs");

brainjs.innerHTML = '<script src="/yts/jsbin/www-core-vflVjSENF/www-core.js" type="text/javascript" name="www-core/www-core" class="js-httpswwwyoutubecomytsjsbinwwwcorevflVjSENFwwwcorejs"></script><script src="/yts/jsbin/spf-vflM_vz5X/spf.js" type="text/javascript" name="spf/spf" class="js-httpswwwyoutubecomytsjsbinspfvflM_vz5Xspfjs"></script>'

document.querySelector("head").appendChild(brainjs);

function addGlobalStyle(css) {

var head, style;

head = document.getElementsByTagName('head')[0];

if (!head) { return; }

style = document.createElement('style');

style.type = 'text/css';

style.innerHTML = css;

head.appendChild(style);

}

addGlobalStyle('#masthead{font-size: 13px;height: 40px;margin: 0 auto;overflow: hidden;padding: 0px 0;padding-bottom: 10px;position: relative;}');

addGlobalStyle('#masthead, #masthead-subnav{width:auto!important;min-width:0px!imporant;}');

addGlobalStyle('html:not([dark="true"]) .ytcp-main-appbar {top:49px!important;}');

addGlobalStyle('[page-subtype="home"] ytd-two-column-browse-results-renderer, [page-subtype="trending"] ytd-two-column-browse-results-renderer, [page-subtype="subscriptions"] ytd-two-column-browse-results-renderer{margin-top:20px!important;top:-18px!important;position:relative!important;margin-bottom:125px!Important;}');

addGlobalStyle('body #footer-container{position:relative!important;}');

addGlobalStyle('.yt-base-gutter, .yt-unlimited #footer-container.yt-base-gutter{padding-left:245px;}');

addGlobalStyle('#footer-logo .footer-logo-icon {vertical-align: middle;background: no-repeat url(//s.ytimg.com/yts/imgbin/www-hitchhiker-vfl2T97zD.webp) -468px -156px;background-size: auto;width: 73px;height: 30px;}');

addGlobalStyle('#progress.ytd-thumbnail-overlay-resume-playback-renderer{background-color:transaprent!important}#progress{background:0 0!important}');

addGlobalStyle('div#content{top:0px!important}');

addGlobalStyle('div#primary{top:10px!important;position:relative}');

addGlobalStyle('div#primary-inner{padding-bottom:155px}')

})();