AFAIK part of the problem is that the experiments needed to provide evidence for these theories either require insane energies, particle accelerators the size o

AFAIK part of the problem is that the experiments needed to provide evidence for these theories either require insane energies, particle accelerators the size of Earth's circumference or even larger, or convenient access to a black hole. This seems like a fundamental problem. If data is out of reach, we're left with nothing but noodling around with mathematics and simulation.