Whatever the resolution of 'real life', what matters is at what point our little eyes and brains no longer can perceive a difference.

In average scenery, the general consensus is about 60 pixels per degree of vision. If you have something a bit more synthetic, like a white dot in empty space, then that sort of specific small high contrast would take maybe 200 pixels per degree to ensure that the white dot is appropriately equally visible in the display versus directly seeing. A 75" display 2 meters out at 4k is about 85 pixels per degree. This is comfortable enough for display.

Similar story with 'frames per second'. Move something back and forth really fast and you'll see a blurry smear of the object rather than observing it's discrete movement. So if you accurately match the blurring you will naturally see and do low persistence backlight/display, you'll get away with probably something like 60 FPS. If you are stuck with discrete representations and will unable to blur or turn off between meaningful frames, you might have to go a bit further up, to like 120 or 144 FPS.