Because of the assumptions based around what constitutes "cheating", players are not only strongly disincentivized from compressing and equalizing the game's audio: they are often outright banned for doing so. If you play PUBG competitively, then you are either damaging your hearing, or you are "cheating".
This is one of many reasons that anti-cheat systems do more harm than good. Once upon a time, anti-cheat simply meant choosing which players you are willing to play with. That system had no trouble accommodating accessibility. Today, that's practically impossible, because servers are hosted and moderated exclusively by the game studios themselves.