I’m currently working on bot detection for web resources - and trust me, it’s extremely hard to distinguish them from people without some client-side analysis. Sure, you can use behavioral analysis, but you need lots of data and, again, expertise in that. Okay, they have the data - thousands of games played daily. Have you ever seen job listing for “game patterns analyst for LoL”? Again, you have to find someone capable - highly payed experts, who will spend some time testing their theories, with no guaranteed success.

“How do you separate good players from cheaters? This low ranked player who just got his second pentakill - is he cheating or smurfing? This weird behaviour - is it because of missing fog of war or are they just communicating over voice chat?”

90% of cheating that is incredibly annoying, that most people tend to be fed up with, is inherently obvious. You get rid of that shit and if someone is within the 99% percentile, then honestly, who gives a fuck, let them try hard.