According to what I’ve read about and experienced, using compatibility layers such as Wine and Proton can give you a wide variety of results, depending on the game.

I agree with this but I generally find that performance is a bit worse, so I'm just setting expectations. One thing Proton does offer is pre-caching shaders which can help games not stutter compared to Windows, so you might get way less stutters even if your FPS is a bit worse than Windows.

I’ve had so much success with Proton in Heroic Games Launcher

You definitely can use Proton with Heroic but you generally shouldn't need to. Wine-GE's performance is very comparable to Proton and usually Proton can cause issues when ran outside of Steam, which is why it isn't recommended to do so and why all these launchers prefer Wine-GE. I tried to make the guide as simple as possible, so I decide to list the best option rather than a list of options.

There are distros designed for gaming that come with lots of stuff already packaged with the installation.

Definitely. I actually do use Nobara which you might tell from one of the screenshots' background. I might do another post on distro choice but I felt like it's a big topic that can get too opinionated, especially with recent Fedora controversies. I didn't want to recommend Nobara only to have a lot of "Well, actually..." comments.

Maybe add something about Steam and its offerings of native Linux games.

I thought about it but didn't feel like it warranted talking about. If there's a native Linux version, you'd hit install and it should work. It didn't really need elaborating so I decided to focus on the things people can need help with.

Great job and thank you!

And thank you for the feedback!