For regular users it’s not recommneded, but it is the standard way of installing it in a CI environment, e.g., Github Actions, et cetara.
The base concern is interfering with existing user-installed python packages and the OS, see Default terminal idea - #2 by ivankravets and the “WARNING” in the docs.
I’ve only ever seen distributations try and package PlatformIO, but these quickly get outdated, as the PlatformIO core is updated rather often, and distributions are slow. Not seen any .deb redistribution of the PlatformIO made by PlatformIO staff yet – right @ivankravets?