As far as I'm concerned, it's up to the user to make sure pip refers to the correct installation of Python. pip vs. pip3 is merely a Debian repositories convention, I believe. On my system:

$ pip --version
pip 20.2.2 from /home/yannick/.local/lib/python3.6/site-packages/pip (python 3.6)

Personally, I'd generally recommend python -m pip always (or python3 -m pip, perhaps, but not explicitly both); there are too many possible bugs with using pip directly. Most recent example I can think of: scikit-hep/particle#269

I like the MSVC 2015 "or newer" change, though.