[pa7x1]

String theory predicts the existence of supersymmetric particles, predicts the exact number of dimensions of our universe (something that by the way no other previous theory is able to do). Correctly predicts the Black Hole thermodynamics (Hawking radiation, BH temperature and BH entropy) from microstate counting and gives quantum corrections to the semi-classical formula. Predicts a bunch of higher and higher energy particles in a tower whose mass ratios are well defined. They are essentially higher energy excitations of the fundamental modes of the string. So on and so forth.

All this is testable and falsifiable, if we had the technical means to access the energies that are relevant for Quantum Gravity. In the meanwhile, scientists can keep trying to derive lower-energy consequences of the theory or devise smarter experiments that can allow us to test the consequences of the theory at the energy scales that are applicable to us.

[ncmncm]

If, every time we look where the theory says and don't find any supersymmetric particles there, you say, oh well they must be somewhere else, that is no sort of prediction at all.

It cannot be said to predict black hole numbers if those were known, and dictated which subset of the 1e500 possible string theories are still under consideration.

Predicting a number of dimensions is no good if there is no slight indication of any extras at all, and no conceivable way to discover any.

There is no circumstance in which no doubletalk can be conjured to prop up the empty tent. Deliver actually measurable consequences, or GTFO.