First of all, I still prefer TypeScript to Python when it comes to language features. So no, I'm not defending my favorite language here - if anything, I'm "attacking" it.
Secondly, I don't really think in terms of defending favorite languages - they all come with strenghts and weaknesses and I think that its important to talk about and acknowledge both aspects even for languages we really enjoy. That's the only way for languages to move forward and improve.
That said, being embedded into an ecosystem for a long time makes us used to its strenghts and desensitised to its weaknesses. This in turn makes it harder for us to really see the ecosystem's standing compared to others.
I'm trying to provide a perspective as someone who has worked in the ecosystem for a long time and has recently started exploring other options.
Are JS package managers better than Python's? Certainly. If you took a sampling of various tools and libraries in Python, would you be far more likely to have them work together than a sampling of various tools in JS? Absolutely.
I'm a relative beginner to Python compared to JS/TS, but I had a chance to work with it more recently. I had no trouble dealing with pip, venvs and poetry. Yes, there were challenges and annoyances but at least it was possible to overcome them with sufficient knowledge. I agree though - Python has long ways to go to improve this.
However, if I compare this with my previous JS experience, its a different order of magnitude. No amount of knowledge would've made styled components work with next's app router - I simply had to start over and make different choices for my SSR framework and UI library (the alternative was to help with Mantine's migration away from Emotion). So what do I do with my other, already well-developed side project that uses Mantine and Next pages router? I can continue to use the pages router, but for how long? Who knows - its not like there is any kind of concept of LTS or even any kind of thought on that topic when it comes to Next.js anyway (e.g. https://github.com/vercel/next.js/discussions/41906)
At the end of the day, IMO the main difference is attitude. There is broad acknowledgement in the Python community about their problems and they're considered important to solve. I don't see anything like that in JS - compatibility and providing continuity is just not something most authors want to think about. Innovation is (still) priority #1
I realize its hard to make a convincing statement about frequency/magnitude/probability/attitude though. Similar examples will exist across ecosystems. What kind of data would convince you that the situation in the JS ecosystem is bad enough that it warrants a priority shift in the community?