TL;DR: A step-by-step installation of Linux Mint on real hardware and setting it up for typical gaming tasks.
I don't really care much for SOG's other content but his forays into Linux over Windows were incredible for demystifying the operating system to a mainstream audience (i.e. people who watch his content).
Some nitpicks:
- Muta should have used the flatpak version of Steam instead of the system package, the Steam client updates itself (with its own runtime and all) so using a system package over just sharing with flathub is a bit wasteful (it does complicate external storage devices a bit since you have to manually set permissions via flatseal but that's it). (Edit: this is just a small nitpick, the native system package is fine as well).
- There should also have been mention of Bottles over installing Wine as a system package as well as things like the Heroic Games Launcher for GOG and Epic Games titles, Lutris is fine though.
- On long term stable release systems like Linux Mint or Debian, Flathub (or foreign package managers like Nix/Guix) should be your go to for installing software, let the distribution itself manage its core system components which I wish he clarified when he saw Flathub taking multiple GBs on first download.
Other than that, Linux stays winning. 
I audibly gasped when I first found out how old most of the libraries are in the discord client. they were updated in canary for better wayland support like 6 months ago and I've heard nothing since. With steam dropping 32bit support hopefully those of us with native steam can offload those libraries soonTM
Don't know you case for Discord, but you should check out Webcord, it works like a charm with Wayland (yeah I'm 11 days late)