Most distros have been shipping Python3 for years, just not set as the target for `/usr/bin/python`. You can run `/usr/bin/python3` currently, almost anywhere.

Most distros have been shipping Python3 for years, just not set as the target for `/usr/bin/python`. You can run `/usr/bin/python3` currently, almost anywhere. And "software that has been gradually going EOL for the last 5 years" is not "packages the user decides they need that day". I'd be very surprised if any distros that ship with Python2 do not ship with Python3 in 2020, and I'd even wager that most will default to python3 by then.