Don’t like that he called some distros pointless. I would have found a better word. Lots on there that I have never used, obviously, because I am not a sadist. I couldn’t tell you what would be good for gaming or not, but flatpaks have made some things easier (or so I’ve heard, don’t quote me on that). And Fedora is a “Devil?”
Anyway. While I don’t watch this channel ever, I am aware of it as a reputable channel for things like this, so it might be trustworthy.
Why are Debian and Arch at the top? Debian is one of the grandaddies. Many distros are built on Debian—MX, Mint, Ubunu, Pop, Zorin, Neon, etc.—and there are many packages in the repos, which are divided into stable, and testing, and unstable sections. So, a Debian base can be stable or extremely up to date. The Debian community and maintainers are another reason the distro is so well-liked. Arch also has a large selection of packages, an excellent wiki, and the AUR to have access to anything missing from regular repos. Manjaro and dozens of others are based on Arch as well, meaning the community is rather large.
No need to follow rules and conventions though. There are many people, myself included, that use Alpine for their desktop because the packages are very up to date.