The Quest Pro has a better design than the Quest 2 (as well as many other benefits), but in terms of pixel density it only offers 10% higher PPD than the Quest 2 (which was already pretty low).[1]
(Disclaimer: I'm affiliated with Simula).
(Disclaimer: I'm affiliated with Simula).
My understanding is that the optics are what destroys readability on the Quest 2, and in that regard the Quest Pro is in a completely different league with the pancake lenses.