So, anti-cheat when?

They may not use the third party software Easy Anti-cheat, but I can assure you that Riot has enough data to tell a robot apart from an actual player and that they do, in fact, ban people who use third party programs. They can also tell individual players apart from one another, so they can tell if someone buys a boosting. The issue with that one is that it takes them having a reason to have a person, rather than their own machine, look into that account's data, so if nobody has any reason to suspect that you were boosted, you can get away with it.

How does one really even cheat on TFT beyond bots