I full time and I have noticed over the years that it is regional. Some states have a lot of propane dealers some seem to have none.
That said. I have a relatively small tank on my MH and due to size of the coach and towing, just getting into some places is not doable.
Flying J was my go to until I got tired of the wars at the "gas" island that also had the propane AND you could come in from both sides.
And then they started demanding that I unload all my dogs before they would fill the tank. Not gonna happen. :R
Flying J is permanently OFF my list for stopping for anything. When I need propane I look up a CG that has propane and arrange to stay the night at and get propane before I leave in the morning. Problem solved all the way around.