Pick whatever the most competent and helpful Linux-user around you uses... The distos are pretty much all the same, just different in the details.

This is really good advice. I'm a Fedora user who has set up several "non-technical" users (quoted because I have qualms about that term) with gnu/linux. At first I was giving them Ubuntu since it's the most common and supposedly "regular person friendly". After multiple experiences struggling to provide advice or support, ended up switching them to what I use. It's just easier when I already know the ins and outs of the system.

Pretty much.

I still recommend Xubuntu for new users since they can leverage the massive package base and stable releases of Ubuntu and move to something like Fedora (or Arch or whatever) later.

Unfortunately, all the "distro picker" resources I have seen so far are of questionable quality. They either are too opinionated (use my favorite distro) or not opinionated enough (listing super niche distros for no good reason).

That said, I agree with what jononor said. Using something similar that what your most helpful Linux-using friend uses trumps picking the most ideal distro and as long as you pick something relatively mainstream there isn't going to be that big of a difference anyway. In my experience, the choice of desktop environment (GNOME / KDE / MATE / etc) is actually more impactful than the choice of distro.

They might benefit from checking out https://wiki.installgentoo.com/index.php/Babbies_First_Linux - includes a nice though two years out-of-date flowchart from /g/.

That might just be the most controversial post on the internet, if indeed it exists.