If you think of the headcount for "private servers", and assume 0 overlap, then private servers tend to have in worst case, 1 staff member per 100 players. Can you imagine any large developer employing a team 1% of the size of their playerbase for community moderation? Wouldn't happen. More likely they have like 10 support people and 3 devs on their anti-cheat team for their million player game, so they need to rely on their technical measures and stick their fingers in their ears as to the existence of false positives and the inevitable loss of that cat and mouse game in long running titles.