My favourite dev tool, rtx, has been renamed to mise and now has plenty of documentation. If you're looking for an alternative to pyenv and asdf that doesn't ruin your environment with shims, and also one that can create virtualenvs automatically on the fly and manage environment variables, check it out!
lololol so I think I found a "legitimate" reason to install pipx with itself
I installed pyenv and then installed pipx with one of the non-system Python versions, but then I set the local pyenv versions in a directory to exclude the one pipx was installed with, thus causing any invocation of pipx in that directory to trigger pyenv's usual warning about the command not existing in any of the enabled Python versions. Turns out pipx install pipx makes it magically work again 🎉
(this is probably where I should put a disclaimer "don't try this at home")
@AlSweigart I use macOS and Linux. It's always pip for me.
To clarify a bit. On macOS I use #Homebrew to install #pyenv and then pyenv to get python. On Linux, pyenv is probably one of the first tools that I install.