Love it or hate it, bootstrap has been a mainstay of front-end development since 2011. I've watched it grow and now, dare I say, flounder.
Rather than recant the ups and downs of each generation, Bootstrap 3 was wonderful for its simple flexibility. Most of the time, I whittled down Bootstrap to the bare minimums, often using only its grid (modified with my own breakpoints) and in-name-only classes like
.btn, as they're lexiconic to bootstrap. Any project, I could rely on like-markup and classes to Bootstrap even if the project was largely not-bootstrap. Bootstrap 3's Sass logic was simple and easy, but bootstrap 4 is silly.
- Bootstrap 4 now uses Sass includes for breakpoints. Why? I cannot fathom a reason a realistic reason why. This is counter-intuitive. Everything is include hell.
- Most of the generative sass logic has been abstracted into mixin hell. It's starting to resemble the clusterfuck that is Foundation.
- The cross-dependency of Sass isn't predictable. Example: If you comment out forms, it will break nav functionality. There's a lot of senseless overhead.
- Lite and dark themes are written into the code in such a way, it's not easily abstracted out.
- While small, some of the icons are inlined SVG images, which means removing if custom icons are used, more senseless payload.
Bootstrap 3 was the right mix of complexity to return on investment, but Bootstrap 4? I'm starting to think otherwise. So far, there's not enough compelling for Bootstrap . Conversion to REM units is nice as well as opt-in to Flex box. Dropping IE8 is a good move. Glyphicons need to go for accessibility. The overall CSS is smaller. I like that. The hackability though? Less so.