Those issues are annoying but I'm not sure they're all that common. The default interpreter is perfectly fine for most cases as long as it's not years behind in versions, and I honestly have no idea where you'd get a Python dependency outside of pip, literally never seen one before. The company I worked for that did a lot of Python code had an internal Artifactory with a pip repo so even private packages went through it.

Cargo is great, I agree it's approaching the usability of running a Python script there. But now you're compiling Rust, which is going to take orders of magnitude longer than any time you'd save from the script itself running faster. Plus for most of the scripts Python is used for from what I can tell, more time is spent writing them than running them anyways. So as much as I do love Rust I'm not buying that it's the better choice here.