That's actually a Windows thing, not a PowerShell-specific thing. The Microsoft Store app generates a stub executable called python.exe and puts it on your PATH

That's actually a Windows thing, not a PowerShell-specific thing. The Microsoft Store app generates a stub executable called python.exe and puts it on your PATH. It'll get picked up whether you're in PowerShell, CMD, or MSYS2 Bash. It's basically the same kind of thing as Xcode's git stub on macOS (which I also find odious). The feature is called 'executable aliases', in case you want something to Google to find out how to disable it.