That is indeed naive thinking (hence personally I buy physical for anything I don't consider disposable). Or rather, it would be naive if they didn't say "Buy"

That is indeed naive thinking (hence personally I buy physical for anything I don't consider disposable). Or rather, it would be naive if they didn't say "Buy" on the button. If they promise an actual sale then, yes, they should be obliged to provide it forever. It's not our problem they promise what they cannot deliver. If they can't/won't then they shouldn't be claiming it is a sale as it's a rental. In other words the issue isn't user naivety it's platform deceit.