Honestly, I don't see me getting the Series X when I have the gamer pass and will probably upgrade my computer again at the end of the year. I don't know what the Xbox Studios are cooking up, but for now I will get Forza 8, Forza Horizon 5, Halo Infinite, Hellblade 2.
For PS5 there are lot of exclusives that I will get, like the next Final Fantasy VII Remake, God of War sequel, Days Gone 2 (just want a better performance, because it was rough to say the least), Silent Hill (if true) , Demon's Souls Remake (if true), Bloodborne 2 (highly doubt it will ever be a thing), the rumoured Legacy of Kain Remake, and some other Japanese titles that are exclusive to it.