Really? I'd have guessed bootstrap will be phased out completely by CSS grid, which does essentially what bootstrap does...
[1]: https://html.spec.whatwg.org/multipage/interactive-elements....
(Personally, I'd rather they just build it in Lazarus, but people have forgotten about building desktop apps.)
Bootstrap is a _framework_, not just a layout system.
Also, BS uses Flexbox at the moment, I doubt they'll go to grid any time soon.
(Which btw is mentally a lot easier than the odd CSS grid syntax)