The only reason we have 10,000 UI libraries in the last 20 years is because we decided to keep default browser UI ugly and bare-bones for some reason.
Like datatables, rich-text editing, toolbars,...
MOST applications are just simpler CRUD UIs. Developing these is still too complex on the web platform.
And Progressive Enhancement has it that our bells and whistles gracefully degrade back to from whence they came.
But browsers don't do that either. And you really, really don't want to make your own controls most of the time. Because: https://drewdevault.com/2021/06/27/You-cant-capture-the-nuan...
Personally, I wish that for accessibility and other reasons, all 10000 frameworks would produce buttons with some kind of metadata that lets a user configure their own settings. But we're quite far off that.