The quiet part needs to be said out loud: ensuring "fairness" in online games and letting clients meaningfully remain in control over their hardware and software are
two fundamentally incompatible goals. One goal puts the interests of the game publisher and community first, the other upholds the individual clients' interests.
Ideally there should be little conflict between the two, however, modern online games require running sophisticated software locally that encapsulates core game logic. The fairness (compliance) goal demands that this software runs correctly and only conveys information and processes input as designed. The user control (freedom) goal demands that the individual user is allowed to run and modify any software as they see fit, including any game software, meaning that he or she must be able to tamper with the game software behaviour to gain advantage.
Now remember that online gaming is an extremely low-trust environment. Competitive online gaming is often supposed to emulate sportsmanship, thus widespread trust in the games' rules is essential so that players continue to participate. At the same time, building that trust dictates enforcing compliance down to the level of each individual user's hardware. So if you want to participate, you must be willing to give up ultimate control over your hardware and software, even if you believe it's only temporary.
All of this might sound very obvious, tautological even. However, lots of comments on this sound like they come from a place of unawareness of this contradiction. More people need to see that this is not a tech incompatibility issue, but rather a more serious values clash. Linux folks are (still) mostly the ones who prefer more freedom and control over their software, and competitive online gaming asks that they give that up. For a lot of people this defeats the purpose of using Linux in the first place.