It also helps that even minor versions introduce breaking changes.
I doubt anyone really knows Python that well, unless they are on the core team.
Of course, that worked because 1) I was really only doing one project, not juggling multiple ones, 2) there weren't all that many dependencies (Numeric, plotting, etc.), and 3) I was already up to my eyeballs in the build system with SWIG and linking to the actual compute code, so I knew my way around the system.
But every now and then I just shake my fist at the clouds then mutter darkly about just installing the dang thing and maybe not taking on so many dependencies. :-)
I’ve done with with plenty of languages including C/C++
The annoyance with venvs is you have to create and activate them. In contrast for cargo (or stack or dotnet or yarn or pipenv or poetry), you just run the build tool in the project directory.
Another limitation of venv is it doesn't solve the problem of pinning a versions of Python, so you need another tool.