Yea, worth noting that the small-tank propane market also works like this. When you go to a supermakert or gas station, you just swap an empty tank for a full one. Refill is done after hours at scale.
The last time I tried to do that (6 months ago) they rejected it. I had to go to the original supplier, as they were no longer refilling each others branded containers. In spite of standard fittings/sizes/etc. They've become significantly less fungible, and I can no longer just go to the nearest or cheapest supplier based on my needs.
Even worse, I've just realised that I now effectively have two un-refillable tanks, as Homebase just shut down all my local branches. Which I paid deposits on when I bought them, obviously. Nice ...