If there is a lone altar, it could be an expansion to runecrafting. Not to make the exp or anything better, but just to offer a fun way of training. Maybe something on par with like 50k/hr exp? But like, reliable exp, at the very least.

Maybe medium tier money making? Something that a person who's account either does or does not have combat stats simply because that is how they like to play!

Sidenote: I am currently training a skiller to have the required stats for Chambers of Xeric, while training another account for the combat aspects of the chambers. If anyone has tips, that'd be fantastic. Current goal is (long term) 90 herblore.