I may be spoiled in that I don’t play AAA multiplayer games, but I do play AAA single player and indie single/multiplayer (usually the type where one of the players is also the server, e.g. Terraria).
Been running Linux on my systems for more than a decade, and - especially since Proton/SteamDeck enchantments made their way upstream - I haven’t had any major ssues (except having to wait a while to play RDR2-PC in Ubuntu because of a weird game-specific graphics card driver issue, but even that was fixed in due course).
Fuck Windows, and fuck the assertion that it’s the only way to run games.
There are absolutely online stores that do that, but they’re usually gamer-focused, so there’s three issues;
Note: I’m taking about laptops, because it’s all I’ve bought for the last decade or more;
The non-gamer focused stores rarely (if ever) have the option (Lenovo, Dell, Microsoft, etc).
The gamer focused stores usually sell hardware that runs Linux like shit because the hardware needs extremely specific drivers (which isn’t necessarily an issue for Linux, but if it doesn’t exist yet, you’re either building them yourself, or waiting for someone else to do so).
The gamer focused stores are usually patroned by people who are all in on Windows gaming, because they don’t do much else with the system, so they don’t experience the kinds of annoyances that power users would gripe about (which is why the above point doesn’t compel those sellers to do anything different).
As for desktops, I really couldn’t say. Haven’t been paying attention for years. It’s possible that you could buy a system without a hard drive, never mind an OS.