Re other theories, I don’t think that all other theories in existence have infinitely many adjustable parameters, and if he’s referring to the fact that lots of theories have adjustable parameters that can range over the real numbers, which are infinitely complicated in general, than that’s different, and string theory may have this issue as well.
Re string theory’s issue of being vacuous, I think the core thing that string theory predicts that other quantum gravity models don’t is that at the large scale, you recover general relativity and the standard model, whereas no other theory can yet figure out a way to properly include both the empirical effects of gravity and quantum mechanics in the parameter regimes where they are known to work, so string theory predicts more just by predicting the things other quantum mechanics predicts while having the ability to include in gravity without ruining the other predictions, whereas other models of quantum gravity tend to ruin empirical predictions like general relativity approximately holding pretty fast.
Re other theories, I don’t think that all other theories in existence have infinitely many adjustable parameters, and if he’s referring to the fact that lots of theories have adjustable parameters that can range over the real numbers, which are infinitely complicated in general, than that’s different, and string theory may have this issue as well.
Re string theory’s issue of being vacuous, I think the core thing that string theory predicts that other quantum gravity models don’t is that at the large scale, you recover general relativity and the standard model, whereas no other theory can yet figure out a way to properly include both the empirical effects of gravity and quantum mechanics in the parameter regimes where they are known to work, so string theory predicts more just by predicting the things other quantum mechanics predicts while having the ability to include in gravity without ruining the other predictions, whereas other models of quantum gravity tend to ruin empirical predictions like general relativity approximately holding pretty fast.