I legitimately can't understand why people believe they have a use case for `sudo pip install`, or ever did. I've seen so much cargo-culting (thankfully, generally it's all old material) suggesting the use of sudo to fix issues with pip and it's basically always at least wrong and generally dangerous. In cases I've seen where it "worked" and a user install wouldn't, it's ultimately because the root user has different environment variables.

(Also, apt-installing multiple Python versions can already mess things up, from the reports I've seen. Building from source and installing it at a custom location that won't mess things up is easy, however.)