Nobel prizes skew heavily towards experimental physics and theory prizes require experimental verification. That's why Higgs had to wait until 2013 even though

Nobel prizes skew heavily towards experimental physics and theory prizes require experimental verification. That's why Higgs had to wait until 2013 even though absolutely everyone was convinced that a Higgs boson existed for decades before that. Even Einstein didn't win the Nobel for GR, but for the photoelectric effect. Back in the day when high energy physicists kept discovering new particles and there was a short delay between theory and experiment, there were more Nobels awarded to theorists for this, and I think that golden age of grand unification progress created a false impression that theory work is expected to win Nobel prizes just for being good theory work. But if you look at the last dozen or so Nobels, they are all for describing observable phenomena or conducting novel experiments: (lasers, discovering exoplanets, detecting gravity waves, theoretical descriptions of phase transitions of matter, LEDs, mass of the Neutrino, etc.) It would take very convincing experimental confirmation before String theory wins a Nobel, but there are lots of other prizes awarded to string theorists, and Witten even won a Fields medal, which is more prestigious than a Nobel to the math community.