I remember in Mabinogi they had created this bomb you could use on players you thought were bots. What it would do is it would force the player to solve a timed capcha, and if they failed it would lock everything you could do for 10 minutes. Repeated failures would lead to an auto-boot.

In theory it should of helped stop bots cold. Reality was very different.

Bots would not even flinch or pause from these things being flung at them repeatedly. They moved as fluid as ever cause they insta solved them.

Real players however would get locked and booted regularly. It was deemed a failure.

Your suggestion would punish legitimate users far more effectively then it would even slow bots down.