Well, they are not in rival consoles. So they are exclusives.You are trying to change the discussion here. Again, how are GT7, HFW, Miles Morales, Ragnarok... PS5 Exclusives?
A person getting into gaming could also buy a cheap PS4 and experience these same games without a drop in quality... So why are they listed as PS5 exclusives in here? Lol
So now we are doing hypothetical arguments? Okay!
Some may be ported to PC, or also be available in their previous console. But not in rival consoles.
AAA games are super expensive to be made, so need to be available to the biggest amount possible of players.
Unless they have some top IP like Spider-Man and a talented team that gives people confidence, so pretty much guarantee them a ton of sales, pretty much record selling ones, the PS5 userbase for many of them isn't enough.
On top of that, AAA games released nowadays require around 5-9 years to be made, the current gen is 4 years old and they had the specs and devkits around 5 years ago. And next gen engines still don't take full advantage of the hardware, need more time.
That means that we are are starting to see the first games designed for this hardware, and many of the current ones and the previous ones were designed and started to be developed for previous gen hardware with previous gen engines and tools.
So there wouldn't be any meaningful change between making a game exclusive or crossgen, to go next gen only would only mean to leave money in the table making it way less profitable, and probably even to lose many millions with the game.