Even if you are the best driver in the world, it takes a lot longer than 3 minutes to unload. Unhook the tiedowns, disconnect truck plugin, lower the jacks to raise the camper (this is the longest part), pull forward from under camper, lower camper to lowest level (the second longest part). I 'd estimate 15 minutes to unload and 20 minutes to load it back up. So like others, we usually leave it on the truck if we're going to only be somewhere for a day or two, and take it off if we'll be 3 days or longer. We usually never stay anywhere longer than two or three days.
We were on the road 6 weeks this year, and used the AC one night. Not a high priority.
I agree that modern campers don't need support under them when they're off the truck, other than for stability as the camper will move bit when you walk around if it's only supported by the jacks.