So now you're at the mercy of your OS packaging system to ship the Pythons you need.

This is actually intensely frustrating, and I have witnessed many people have their systems break with this (a similar example is when brew updates postgres and suddenly everyone is like "where is my data?" because brew has decided to change what is canonical postgres).

I think the core lesson of Python's distribution pains is to never trust the OS packagers to do the thing that will be easy for developers. Whether it makes sense for deployments is an open question, but I think it's worth considering why everyone ships adhoc python images rather than just relying on apt