Ok but Go compiles statically, while you can do the same with pyinstaller, I don't think that's really comparable as we're talking about deployment right there.
Sketch for python: Create a ~/.cache/python/packages directory. Manage all dependencies there. Make the python interpreter "package aware" so that required dependencies are read off a file from the current project (e.g. "py.mod") and adjust "system path" accordingly and transparently. Or something along those lines.
No extra tool, a single location, an easy to explain workflow (add a py.mod file, add deps there with versions, etc).
I'm just thinking out loud, but it does not need to be hard.
Are you saying "put the different version of every dependency you need in there if you have to"?
Because I don't think package managers are ready for that, they usually like to have one version installed per package.
That's on them. Other language package managers can do it...