With MMOs you can actually reverse engineer the network protocol and build yourself a custom client. Completely avoids any anti-cheating solution since they're not even running.

With mobile games it's ridiculously easy. I actually made daily task farming bots for a couple mobile games I used to play. The hardest part was getting the bot to log into the game. Completely neutralized the habit-forming strategies of these game companies. Ironically the bot was statistically indistinguishable from any sufficiently-addicted player.