In Oldschool Runescape it's pretty common to see characters that are just blatantly bots. If they had plausible usernames and picked a random appearance it wouldn't even be that obvious, because it's a whole game about repetitive actions, but a lot of them have the default appearance and gibberish names.

Botting is sort of a different problem because it's often related to real-money trading, so there's a more obvious incentive to cheat: running bots generates gold that can be sold for cash.

In addition to that, many people run bots as a sort of side hustle, either to fund their main or just to fund more bots. And I suspect many people use scripts to automate tedious tasks on their main accounts as well, although that would be hard to notice unless you directly interacted with them while they were AFK.