Two versions of a game will look/run differently in the same ecosystem. Some games will not release on the weaker platform if the game is really demanding. And many people will see this and decide their purchase is not good enough and buy a second console, which is basically near identical to the one they have and pay premium for that.
Consoles are not PCs, you buy it expecting it to last as many years as possible. You don't want to spend that much money every couple of years, mobiles are bad enough for that, I don't want that business model for consoles. If you don't mind upgrading every now and then, you get a PC.
List one game released on PS4Pro that didn't release on PS4, or X1X that didn't release on X1.
duduspace11 "Well, since we are estimating costs, Pokemon Red/Blue did cost Nintendo about $50m to make back in 1996"
Mr Puggsly: "Hehe, I said good profit. You said big profit. Frankly, not losing money is what I meant by good. Don't get hung up on semantics"
Azzanation: "PS5 wouldn't sold out at launch without scalpers."