do they even sell disc of these game?...

They do, but it's irrelevant to performance nowadays since you're required to install all of the disc data to the SSD before you can play. The PS3/360 generation was the last time you could play games directly from a disc (and even then some games had an install process).

	▲	Cthulhu_ a day ago \| parent [-]
		I believe even then it was already "most", at least for the PS3; that was the era where always-online devices became the norm, where game developers were more eager to release patches after release, etc.