Who would you say is worse, someone who thinks the world revolves around them or someone who thinks they are right about everything?

You’re describing the characteristics of the same person.

Someone who think they are always right—and almost always are in fact right—can be annoying but also useful.

It’s the same picture

Does it need to be a competition for which one is worse? They are both equally annoying.

As someone who is always right, I can definitively say that when someone wrongly thinks the world revolves around them, they are the most annoying thing compared to someone simply being wrong in my presence. They should know the world revolves around me smdh.

Legit though, solipsistic narcissism is more entertaining than inaccurate pedantry, so I go with the knowitall

They would overlap a lot. The parson that thinks they’re always right will have never bothered to learn anything, nothing more dangerous than an idiot.

Those are often the same person