Living at Dodo house is largely for ease of use! You can assume various unpleasant too-real reasons for why old AU homes are no longer an option -- termites, rent hikes, sudden roof cave-in, etc. Dodo has free food and board, so it's just the most convenient option, especially for characters that aren't making much money to begin with! After a few months of effort (and fiscal responsibility), it's reasonable to assume characters can afford to move out, but it's always an option to rent an additional office/hideaway/etc instead of leaving Dodo entirely.