I've watched a few reviews where the claim is "multiple 4k monitors", and even on Apple's site it says "More pixels than a 4K TV. For each eye.". But any virtual monitor is going to be scaled down, and with "spatial computing" being the desired interaction, it's not going to be projected at a fixed point on the embedded screens. Sure, when you have a 4k monitor across the room, it's smaller because it's further away, but the full resolution is there (reality is much higher fidelity than "retina display" ever was and even the Vision Pro is). When a virtual display is projected into a space further away, it's going to take up fewer pixels and be down-sampled. It's kind of annoying that the term "4k" is being used to refer to "physical space the display takes up" or "size reported to the operating system" rather than the physical pixel density.