Let me start by saying I think Linux Mint is one of the top 5 greatest distros of all time. It is an absolutely essential starting point for many people and their work is responsible for much of the user-friendliness you see in the world of Linux today. It is stable, has a nice aesthetic, “just works”, and doesn’t make you update constantly.
These things are great but they are the very things that make Linux Mint unsuited for online gaming. Is this a bad thing? No!! It’s just not a distro made for gaming purposes. It’s like showing up to a monster truck drag race in a Ferrari. I cannot count on my two hands how many times I have provided support to a user, to find their issue was outdated libraries due to using Linux Mint. It happens all the time. Go look at any game on ProtonDB that is currently working, and you’ll find 1-2 “not working” reports and they are always on either Debian on Mint.
I understand why we see it so often, because Linux Mint is awesome and users want to play their games on it. But if I suggested Hell Let Loose to a friend using Linux Mint right now, the first distro suggested for gaming in our FAQ, he wouldn’t be able to play because of his choice of distro. Making rolling distros look like a fortress in 2023 and suggesting Mint for gaming will only set new Linux users up for disappointment.
It’s more than only Flatpak libraries and such.
Flatpak still talks to the kernel and mesa drivers. So if your stack is stable, but not more close to the edge, it can be problematic for gaming. I like to think of them as a inner and outer ring, both need to be optimized.
I think that’s one of the reasons Valve chose Arch Linux as its base. In most cases bleeding edge offers more performance, but may lead to potential data loss and such. Fine for a Steam Deck, but not much for a desktop distro.