I don't know that infinite housing is the correct solution. Part of what can make things desirable is scarcity.
Better to have a dual system.
First, a fully instanced system (not the current apartment system) that guarantees each player and FC one plot of their choosing. If the farm mentioned at Fan Fest isn't intended to give all players access to the gardening system regardless of house ownership, then gardening could get incorporated into the new instanced housing. Same with FC workshop. Outdoor item limits could be increased greatly for these instanced plots since the game would no longer be trying to also load items from neighboring houses. Being fully instanced, there would be no need for demolition so a player (or even a FC) could take a 6 month break and come back to their plot the same as they had left it. It's not a truly infinite system, it's just one that's flexible as the size of the player base changes.
Second, the ward system converted into a competitive system for those who consider housing their end game and are willing to pay for the privilege of obtaining additional plots. Purchases would be personal only since FCs would have their guaranteed plots with workshop access.
There would still be requirements and limits for the sake of fair competition. The player would have to have a character on a world that meets level and rank requirements to purchase and maintain houses on that world (no transferring one character world to world to buy up houses then leave the houses in the hands of a level 1 character). They could still put a limit on the number of ward houses that could be owned by an account (perhaps one per housing district per world). They could tighten demolition rules and/or add in monthly fees so ward houses are more likely to become available to other players instead of hoarded by a few.
This way housing is obtainable for everyone but still offers features to make it desirable as an end game for those who have a greater than normal interest in it.