This is so funny because rust has one of the worst cheating situations and majority of their players are windows users, and theres lots of games that have anticheat that allows linux and have notably less significant cheating problems like marvel rivals. in reality rust doesn't take cheating very seriously because if they did they would have more server side software that detects illegitimate behaviour like tons of other games do successfully...... even most popular Minecraft servers have better functioning anti cheat that is completely server side than rust has while getting kernel access to your pc. its pathetic and lazy development tbh and this entire post from them reads like such extreme cope....
It will ruin the experience for anyone playing competitively in a ranked mode, which means invalidating that mode entirely. This drives players away from competitive games like CS, Valorant, etc. which is why those games all use anti-cheats.
Similarly if there is a persistent world or some state that the game relies on to make the game fun for everyone, e.g. extraction shooter, MMORPG, etc then if the game state's integrity is compromised it loses meaning entirely. Imagine playing chess but your opponent can move the pieces any way they like; it stops being a game.
I do agree that games where everyone agrees on cheating should allow it.