Putting aside the fact that you cannot "experimentally prove" anything as proof is for mathematics, claiming you can experimentally demonstrate fundamental uncertainty is, to put it bluntly, incoherent. Uncertainty is a negative, it is a statement that there is no underlying cause for something. You cannot empirically demonstrate the absence of an unknown cause.

If you believe in fundamental uncertainty, it would be appropriate to argue in favor of this using something like the principle of parsimony, pointing out the fact that we have no evidence for an underlying cause so we shouldn't believe in one. Claiming that you have "proven" there is no underlying cause is backwards logic. It is like saying you have proven there is no god as opposed to simply saying you lack belief in one. Whatever "proof" you come up with to rule out a particular god, someone could change the definition of that god to get around your "proof."

Einstein, of course, was fully aware of such arguments and acknowledged such a possibility that there may be no cause, but he put forwards his own arguments as to why it leads to logical absurdities to treat the randomness of quantum mechanics as fundamental; it's not merely a problem of randomness, but he showed with a thought experiment involving atomic decay that it forces you to have to reject the very existence of a perspective-independent reality.

There is no academic consensus on how to address Einstein's arguments, and so to claim he's been "proven wrong" is quite a wild claim to make.

"[W]hat is proved by impossibility proofs is lack of imagination." (John Bell)

Einstein wasn't talking about anything at all, since it's a misattribution. Einstein never said that. Someone just stuck Einstein's name in front of their own stupid garbage quote to make it sound smarter.