I would look at this comment[0] by sametmax for a critique of pip. My main gripe with virtualenv is that it's required at all: other interpreted languages, like node and elixir for example, have figured out how to handle non-global dependencies without a third-party package. Beyond that, it's frustrating to deploy because its non-relocatable (in our build/deploy scripts at my last python job we had to use sed all over the place to fix paths), and I find it semi-annoying to have a bunch of different copies of interpreter and all that goes with it (though this is mostly a minor annoyance -- it doesn't take up that much space and it doesn't matter if it gets out of sync.
Also notable, IMO, is the lack of a tool like rbenv or rustup for python. I can't tell you how many times I have had to try to figure out which python version a given pip executable worked with.