I forgot about air conditioning. We don't need it here or where we go in the RV either, so not a factor.
Makes sense if you need to run anything else plus the air conditioner.
Makes sense if you use the RV as a "guest cabin" in your yard too, when they need air conditioning.
Air conditioning for dogs is valid, of course. Some dogs just don't know when to quit at events, and have to be thrown in a water tank to save their lives. Air conditioning in the rig at home where they can over-heat doing practice runs makes sense.