What would be even better would be to completely remove the requirement to activate or deactivate the virtual environments.

If someone runs python it should look for a .venv directory in the current working directory. If it finds one, it should use the python interpreter located in that virtual environment instead of the system one. Obviously a flag can be used to disable this behavior and run the system interpreter no matter what the current directory is.

There’s an argument to be made that it should search upwards in the directory tree as well. In case the current directory is /home/user/myproject/otherdir/deeperdir/ and the .venv is in /home/user/myproject/.venv/ then the venv should still be used.

This not only saves a lot of trouble for users in the terminal, but also for various shell scripts, systemd service definitions, etc. Anyone who wants to run a Python program correctly just has to make sure they cd to the correct place first. Then they can just run python without having to know anything at all about virtualenvs.