Not being able to 'at-will' sell your house is intentional for the very reasons that AnPo pointed out.

Changing how housing is acquired just shuffles the deck chairs and solves nothing. There are several options that Square can take to actually address the housing crisis instead of hand-wave changes hoping we'd just shut up about it.

We believe the Island Sanctuary feature will decouple gardening from yard ownership. They still need to decouple workshops, submersibles, airships, and aetherial wheels from guild house ownership. That removes the most of the pressure to acquire housing for functional reasons.

Apartments should be reworked to offer different sized floorplans (apt, small, med, large) with the corresponding content limits and offer options to add on an exterior.

Or they could just bite the bullet and implement instanced housing like they should have in the first place.