JS doesn't really have the tradition of external modules that Python has, for a long time it only really existed inside the browser.
On the other hand, rewriting the C modules and adapting them to a different C API is very straightforward after you've done 1 or 2 of such modules. Perhaps it's even something that could be done by training an LLM like Copilot.
That's breakage you'd have to tread carefully on; and given the 2to3 experience, there would have to be immediate reward to entice people to undertake the conversion. No one's interested in even minor code breakage for minor short-term gain.
Which is why I'm shocked that Python's big "we're breaking backwards compatibility" release (Python 3) was mostly just for Unicode strings. It seems like the C API and the various __builtins__ introspection API thingies should've been the real focus on breaking backwards compatibility so that Python would have a better future for improvements like this.
The JavaScript VMs often break their extensions APIs for speed, but their users are more used to this.