CSS? Put that sh!t in feature freeze, like, yesterday. Because javascript.

Javascript? Put that sh!t in feature freeze, like yesterday, because wasm.

Except... at least the reflection API's seem to "get it"—that you can't just keep adding features willy-nilly. I'll take a new metaprogramming feature that deprecates an equal number of old ones. And if you look at the MDN article the OP referred to, the reflection API is apparently intended to obsolete several existing built-ins. And as the OP also indicates, Proxy also lets programmers implement things that would otherwise be the VM's job.

But of course, unlike the auto industry, we can't actually realize obsolescence, so, like I said, I agree with you.