I don't even mind[0], I think it's actually kind of amazing.
[0] I have all the usual complaints about build systems and about the node ecosystem in general, but I don't think the fact that it's javascript compiled to javascript in and of itself is a problem, only, well, almost everything about how that's usually implemented/achieved :D
OTOH I haven't seen a pure JavaScript project for a number of years. It's all Typescript now, maybe with some vestiges of legacy JS slated for eventual migration to TS.
Much, not so much.
I see JSX as basically 'compiling augmented javascript to javascript,' much of decorators is much like that as well, and things like e.g. vue's turning expressions on its reactivity based signals seen in templates into something more clever is also in the category I was trying to gesture at.
(TS is awesome but I should've predeclared that it wasn't really what I had in mind, sorry for any confusion induced by that mistake on my part)