It was not their action, nor is it hacked, nor is the message contained within pip.
The system works by pip voluntarily recognizing a marker file, the meaning of which was defined by https://peps.python.org/pep-0668/ — which was the joint effort of people representing multiple Linux distros, pip, and Python itself. (Many other tools ignore the system Python environment entirely, as mine will by default.)
Further, none of this causes containers to be necessary for installing ordinary projects.
Further, it is not a problem unique to Python. The distro simply can't package all the Python software out there available for download; it's completely fair that people who use the Python-native packaging system should be expected not to interfere with a system package manager that doesn't understand that system. Especially when the distro wants to create its tools in Python.
You only notice it with Python because distros aren't coming with JavaScript, Ruby etc. pre-installed in order to support the system.
