Xbox Series X: 0 Exclusives
PS5: 6 Exclusives

If we exclude all games that
>are on earlier versions of the consoles (ie, Xbox One or PS4)
>are also on PC/other platforms
then that's it.

I haven't found any games on Xbox Series X that can't be found anywhere else, and have only found 6 on PS5.

A list of PS5 exclusives:
>Astro Bot
>Demon's Souls Remake
>Horizon: Call of the Mountain
>Destruction AllStars
>Firewall Ultra
>Silent Hill: The Short Message