GTA World is a miniaturized version of real life. Unfortunately the distribution of players to properties in ALL areas doesn't match-up. When it comes down to it, there's just less residential properties in the county, to the amount of players that used to / do actively roleplay there.
Saying things like "fix the housing crisis" doesn't really work. The same patterns are just going to loop and repeat. Even if in an extreme case scenario all residential properties in the county were revoked, then slowly distributed back to players who can prove they actively roleplay there. They are just going to get resold to non-county players overtime without a leasing rule in place; one potential fix could be if these properties are treated like leases and given back to Property Management upon player's request to no longer live there.
One of the largest issues with the county and it's property availability is that there is no multi-interior properties for sale. In the city, however there are numerous low-end cheap multi-interior apartment buildings, as well as more expensive multi-interior apartment buildings. You can look at the GTA World Map right now and see over ten multi-interior apartment buildings all with at least one property still for sale.
Now, this isn't a fault of GTA World that there are no multi-interiors in the county, it just comes down to Rockstar's creation of the game; none of the viable residential apartments in the county can realistically be multi-interiors. I don't know the plans of Property Management, and how they plan to remedy these issues. But, I do have a suggestion in-mind.
We all know of the derelict motel in Sandy Shores. I cannot remember off of the top of my head how many motel rooms make up this apartment, I believe it to be somewhere in the ten to twenty range. It is currently the only motel / apartment building in the county that is not being optimized, and understandably so it's a dilapidated meth den.
I do not know how realistic, viable or possible it is for Property Management to do this, but applying some temporary band-aid fixes to the location, through adding some small exterior mapping, could transform this location into another ownable (not rentable) location in the county. These could be priced at the county standard price of $35,000 and only distributed to players who are actively showing roleplaying in the area, or alternatively distributed through a leasing system.
Alternatively I think we've all seen this mod, however let's be real. It's a tad over the top for Sandy Shores and would be ridiculously resource intensive for the server to upkeep.
Thank you, for coming to my TED talk on the housing crisis.