I suspect that machine learning might be the only path forward for tackling these issues but even then sophisticated bots will probably still exist.
Some have played their entire life and bot because they want to get ahead. Others bot because they don't have the freetime. It's complicated. As long as you don't really abuse it, Jagex has never really banned for this stuff. The idea here is that you don't get banned because it means losing a potential life long customer, sometimes they subscribe for a few months on and off but they eventually usually come back. There's a lot to it, in reality it's really obvious. Most of the more advanced ones just send packets, though that's another story and it's very obvious. Jagex just doesn't immediately ban them because well, there's not really a point.