As pointed out in the other thread this is right can of worms and the use of sudo is desirable to get the pip installed packages to align with the distro installed python packages. The “purists” advice in that discussion is good if you have also done all the other recommendations and are running everything under your own user and in a virtual env.
I hope that page is not changed, unless a better way of managing the packages is rolled out first. The simple way to avoid using sudo pip is don’t install any python packages that cannot be installed via the OS package manager. Just not using sudo will cause many more issues than the relatively low chance of malicious code being run as root, TBH, even if the package was installed under a non-root user, most scripts (on here) tend to be run by root or as pi with sudo. So the malicious code could still get in and be run as root.
Again I point out I’m not saying it’s right, but it’s definitely the lesser evil and a necessary evil IMO.
PS that link doesn’t work (“not found”), either you meant https://github.com/raspberrypi/documentation/blob/master/linux/software/python.md, https://github.com/raspberrypi/documentation/issues/1752 or maybe https://www.raspberrypi.org/documentation/linux/software/python.md as per my last post?