[shados]

The parser features are fixed. The plugins enable/disable them, but they're already "there", just toggled. As far as I know at this point the parser is not pluggable. Babel is a playground for the official TC39 proposals so it might get stuff a little early, but that's about it.

Where the plugins shine is when compiling those (part of the standard) features to something interesting for production. Better inlining, adding debugging and instrumentation, compiling away certain things, optimizing your views for performance, etc.

All things that don't change the language whatsoever, but can improve your debugging or production experience.

That can be done in TS world (and is quite common) by targeting ES6 and piping the result in Babel though. It's just annoying.

You do have things like Prettier not being compatible with TS because different parsers, though.