Huh. Come to think of it, when I was on Windows (through 2021) I got used to using `python` rather than `py` while using venvs, even though it was apparently no longer necessary after I upgraded from Python 3.4. This announcement totally missed me. But also it was easier to internalize "always use venvs, and always run `python`, and that way you won't have to change the instructions for Linux/Mac". And that worked out beautifully.
But the launcher does have value. Mainly because of how Windows handles the PATH and how it wants C:\Program Files to be organized; but there are enough fringe benefits that a core dev wants to bring it to Linux/Mac too (https://github.com/brettcannon/python-launcher).
It seems to me py launcher could have done the same thing as uv such as downloading and setting up python and managing virtual environments.