Nice in theory, in practice I remember having to support Internet Explorer about 4 years ago. Hard to justify the investment sometimes, at least polyfills gave use some sanity back. The only reason to do it was: Rich old enterprise customer who can't install chrome due to policies created by Dinosaurs.

Websites are surprisingly hard to maintain long term, specially for a broad audience of devices. Developer Experience can lead to better UX, the easier it is to build/maintain, the more likely we're to do it.

Given how bad AI is at design plus all the unstoppable slop train, I expect websites to become much, much worse.