I think this happens because in the ML world particularly, there's an unusually pressured situation.
Why are people not using the system python? Perhaps it's too old or not old enough for some library that they have to use. This suggests there's a lot of change going on at the moment and it's not all synced up. I also suspect that people are using a very great number of different modules that change incompatibly all the time and ontop of that they need binary libraries of various kinds which are quite difficult to build and have all their own dependencies that python cannot install itself.
Rust has the advantage that they can build a world more completely out of rust and not worry as much about what's on the system already.
I'm glad uv is helping people.
> Why are people not using the system python? Perhaps it's too old or not old enough for some library that they have to use.
If you're on a "stable" distro like Debian or Ubuntu LTS, that can be somewhere around 5 years old at the end of the stability period. And your system probably depends on its Python, so if you need a newer version of a library than the system's package manager provides you can't update it without risking breaking the system. Python itself has added several very nice new features in the last few versions, so anyone stuck on Ubuntu 22.04 LTS with Python 3.10 can't use newer Python features or libraries through their system's package manager.
I get it, but one can "just use Artix" or Arch or one of the other rolling distros where everything is always new. The only reason for being wedded to Ubuntu IS long term compatibility and that feeling that Ubuntu will fix security bugs but otherwise keep things "old".