They have nothing to do with it, because what makes something real and unreal is arbitrary. The story just decides what is real and unreal.
You can have two identical worlds. Everything exactly the same. But one is unreal and one is real. Real and Unreal aren't things you can add up to or reach. They are characteristics that are either applied or they aren't. Nothing will make something more real unless the story outright says it is.
No matter how many x there is, you will never be real. IS true for any variation for x. Dimensions, puppies, universes, etc. etc.
You can do the same things for things like abstract. No matter how many dimensions you arbitrarily stack, you will never become abstract. Are we going to claim that because no amount of dimensionality will make something that's not abstract, abstract, that being abstract requires a greater attack potency from dimensions?