You hit the nail on the head. Apple needed to add a whole in-app purchase interface to the store UI to make it clear that the free game you’re about to download charges $50 for berries and the game is practically unplayable without them.

They now need to categorize apps as requiring a subscription as the only means to “buy” it or even just use it.

If the software is free to download but requires a subscription for the service, the button needs to say “Subscribe”, not “Get”. And the app info needs to show you, in loud type, the minimum buy-in cost.