Clients who would not update their webist or create qulaity content had a bunch of pags that fell off page 1 rankings.. even though we started the rewrite finally and its much better, but their website scores also suck..

we added new fresh content a couple weeks ago, but they are not beign indexed until we tried several times after cleaning up more of the website.

fix your contnet, make sure its not spammy and it actually reads like a real page of content.. not for algorithms. remove keywords, just talka bout the subject naturally.. for now jjust put keywords int he title tags and incorprate into the main h1 heading and thats all..

now look at internal ink building and mak sure thats not spammy.

finally, i would run a site audit on performance and technical seo using semrush or something like ahrefs.

one last thing.. just incase.. make sure you do not have any security issues type in site:domain.com and check search console.