I would be careful taking these kinds of ideas too seriously. This starts to get too close to metaphysics for my liking, and I don't believe any physicist genuinely believes or could verify this if they wanted to. It's akin to quantum woo in my mind.

Also, as the other poster already said, saying "quantum theory" is a better description of the universe is nonsense; they describe entirely different things. Although it is no secret they are incompatible as of now, this just indicates one or both may be incomplete but not entirely wrong.

General Relativity is regarded as the accurate description and cause of gravitation, but the Newtonian formulation is a very good approximation in most cases.