The binary installs aren't that generic in the machines I've used (mac and debian based, so covers a fair bit).

It's python3.11, not python3, and the python3 "executable" is, itself a symlink to the particular binary (in this example python3.11). Upgrading just changes the symlink, which wouldn't affect the venv, which isn't using python3, it's using python3.11.

I didn't introduce anything, I explained how the links are to the versioned binaries, which isn't what you're stating is happening.

Edit to add: as someone else also points out, you don't even have to use the symlinked versions, you can use --copies