I'm different. The appeal of owning the game on cartridge to me is to have the entire game on the cartridge. If any significant portion is downloadable only, I see no reason to not just download the whole thing.
I can understand your argument completely though. It just feels like a waste of material to me when the cartridge doesn't carry the game(s) itself.
I've used Pocket Cast for a long time now. I bought it probably about 10 years ago. It recently went open source.