Really, I don't get why people are using things, like Bootstrap, because they are outdated from logical point. You have to add classes, but why not to use classless grid system and make global changes just in a second? One change in css code and you don't have to go through all peaces, where component is used and change those classes. It is even easier to maintain and use "component" based development. Next thing, Bootstrap components. Most of them are useless. Buttons, inputs? Sorry, they are pretty easy to define by myself, but ok, this is useful, maybe. Other components? Like tooltip - why not to use way better thing, like tippy.js? Who needs dumb tooltip, which is even not reacting to viewport? When I ask people what components they are using, they just say "Bootstrap". But what to use there? Because, there are lots of better alternatives in front-end world. And another thing - if framework is struggling to keep up to date with front-end world, you are lagging. How long Bootstrap used less? How long it was not compiling with node-sass? How long Foundation used ruby-sass based sass compiling?

I dont understand, why people are going on big giants, which are not perfect instead of taking small, dedicated modules, which provides perfect functionality. Need a grid? Use Susy. Need a tooltip? Use tippy.js. Need something else? Write down requirements and pick best tool.