More stable than python that's for sure. You could just go with react or node (depending on your use case) , pick a build tool, and be set for half a decade. That's absolutely not the case with Python, and I'm not just talking about the breaking changes that happen in some releases. You also don't get a mess of venv, conda environments, incompatible packages, having to use docker to deploy your app, etc. I use Python a lot, and I like it, but Javascript is much more stable as a platform for quite a lot of what python is generally used for.
Hopefully, but I doubt it'll do so any time soon. Even if it does, JS will still have momentum because of the lack of tooling and setup needed to use it. It's still gonna be in every "intro to web dev" tutorial ever for many more years to come