It actually is how it works.
Wards are persistent loaded instances which contain all the data because the server I/O load is within an exact, controllable expected value (because the wards have a finite number of houses), hence why you don't get any queues when you want to go to your house.
Loading persistent housing data for every single player who would ever buy a house is a titanic server I/O load, meaning it would 100% be relegated to the instance server if they were to ever implement it. Which would cause everything in Seraphor's post to be true.
No, but as someone who's done actual coding projects before, I've had to tell Clients what they desire is basically infeasible without having to do giant re-writes of the foundational code they stuck me with, or have to effectively explain why certain systems they've implemented clash with each other and basically render systems they desire to implement infeasible.
Just because one project can do it doesn't mean another can do it. Or at the very least, in a way you desire it to be so.
FF14 uses the instance server for handling instances. it doesn't take a 3000 IQ to realize that any form of 'unlimited, truly instanced' housing will have to use the instance server to handle it, which causes every problem Seraphor mentioned to become true. People can request it all they like; from a technical standpoint, its infeasible to create Instanced housing without basically gutting content development for a patch cycle or two to re-write giant swathes of the game's instance coding. And since it'd actually halt content develpment...it actually is impossible. You think the CEOs at Square will think Yoshi-P is in his right mind to halt content production for an issue like this?
$$$ talks. And the money is far away from housing. People can request anything they like; but they should also be realistic in their expectations. Hence why people like me & Seraphor explain it how it is to temper those expectations.