so I tried to pixelcount this by using the firetruck on the right
and my count comes down to either 2.088p, 1.944p or 2160p
it's really hard to get it down, BUT this tells me this is a 2160p image most likely, at least on Series X, it's way harder to tell on PS5 due to the image looking softer (AA difference). and it most likely uses checkerboarding as well. so 2160cb
it's really hard to tell tho, here's my sample... and I'm not sure how many steps I can actually count here as the post processing just completely fucks you over here lol
top is Xbox, Bottom is PS5
again, PS5 ran at 51FPS and Series X at 58fps in this exact screenshot. maybe a lower framerate could also explain why the PS5 looks softer, but I'm not sure. maybe there's a dynamic res in place here