This topic is meant to replace the one I wrote last year, which was far more messy, I thought, and also covered pip. (Look in the edit history to see what was there.)
@linux-aarhus gave this new one a 
flag – now I wonder if he had read all the details. 
Anyway, this is now a wiki post that others can work on, and I would rather drop out than get into debates, as I don’t really have that much time.
But this is for noobs/newbies (I hate those words 
) who do not know how to (nor even that they need to) upgrade the python packages that they previously installed, wherever they got them from.
There were a lot of questions in the update announcements about python packages not working, so I wrote that post last year to help them out.
It was messy, so a few weeks ago I tried to write a neater version.
As far as those noobs are concerned, they ( don’t care / are not aware of ) whether they got a package from AUR or PyPI, and I thought it would simplify their situation if they use only pip and avoid AUR for python packages. (Should add a note advising them to install only via pip in future.)
Some people complained about directions to use pacman and yay, saying we should advise to use homegrown pamac, so I did that, even though I use pacman and pikaur for myself.
Conclusion: for noobs it would work as is; the objections seem to come from experts who don’t realize it’s for noobs.