Not really a surprise with 0 AA applied. I'm not sure what you are trying to prove?
Anyone who says they play the latest AAA titles on a 4K screen with a single GPU "maxed out" is either lying or does not know what "maxed out" means.
Does 4K really need AA? I apologies if that is a naive question. I imagine it would benefit from some but having never seen a comparison with and without at this resolution I honestly don't know if it is required.