The horse that I part-board is kept at an equestrian community that is in development. It is very basic - indoor arena (decent sized), outdoor arena and plenty of hacking. No party rooms, pools, tennis courts. etc. So far, the developer has just sold lots and built the road - no additional houses have been built.
The premise is that the horse owners will keep their horses at home, and have access to the facilities. The indoor boarding & outdoor boarding spots are full at this time by horses owned by non lot owners. Maybe that will change once a house or two is built.
It’s a nice concept for sure, but I can see the need for a larger indoor at some point (4 horses makes it feel crowded at its current state), and maybe another outdoor arena added. As with everything, money plays a factor and I am sure they will expand when a need is demonstrated.