Well this is the issue, digital can be erased and removed whenever a publisher feels like it. Nintendo and Sony both closing handheld stores so you cannot reclaim prev bought titles. Emulation is great but sometimes these games are tied into online services.
Real mess but as you say, remaster, re-release and get people to rebuy.
Moreover, with physical, since developers cannot be arsed to make a complete game, unlike most in ye olden days, your game cart requires a day one patch or some crap. So when that store is closed you are stuck with a buggy broken physical cart .. which at least has some resale value, on the brightside!