I will say that the apartment system is not tenable for instanced housing; it can run out, after all. A true solution would require every character (or at least, account) to be guaranteed a house upon creation. And the problem is that they have said that the current housing system can't scale that way.

The island sanctuary is closer to what we need, but interestingly, it's only outdoors. Given the weird things involving internal housing, I personally believe that's what is holding back housing.

If so, to have instanced housing for the internals as well as outdoors, we would need "Housing Reborn", go scorched earth on the current system and build one up that is built properly. I've floated the idea a few times, and the general consensus is that "the playerbase in general would hate that".

Or maybe we'll get lucky and SE figured out a hack that can give us the golden egg. But would it be worth devoting manpower to that rather than some needed QoL or training new staff or new interesting player facing systems...? Say what you will about Yoshida, but I don't want to be in his shoes.