> Yet this says housing costs annually would be $12000. How?

Having roommates is extremely common.

There are also a lot of room-for-rent situations that don’t show up on the websites listing apartments. If you’re tapped into local networks of younger people there’s always someone with a room for rent or a group of friends looking for someone to take over a room in a house they’re renting together. Not helpful for someone in their 50s moving to a new city, but for young people living on a budget this is just how it works and has for a long time.