Going from PS4 to PS5 is free because the license through Sony was already paid for. Same with Xbox, if you paid a license fee to Microsoft it doesn't matter what generation of Xbox you play it on. Going from console to PC is a whole different thing. Sony won't give up the money you paid for their license to go to a competitor. Same for Xbox. Like buying a Dodge and expecting Chevrolet to honor warranty work... not going to happen.