Are directives #AngularJS version of web components?
We could consider using #polymer (https://www.polymer-project.org/). It's basically just filler to be able to start using web components today and it'll adopt future standards so that eventually we can just use native code. They have a host of included elements and their paper elements support #materialdesign.
It's actually pretty cool, and I've started using it on some production projects that don't require legacy browser support. It has flexbox for layouts, so it's super cutting-edge.
One might make a case that it would be possible to use it instead of Bootstrap, which would eliminate the need for both the Bootstrap and jQuery libraries. While it's not as complete as Bootstrap, most elements that would be needed are there, and missing ones should be easy to create. It a lot of ways it's considerable more advanced than Bootstrap.
Obviously, it has it's advantages and dis-advantages like anything else, but might be worth checking out, at the very least. The major downside, as noted, is browser support in IE for flexbox.