I was planning to make a similar comment. Conjecturing that some theory in the string theory landscape [0] gives a theory of quantum gravity consistent with experiments that are possible but beyond what humans may ever be capable of isn't as strong of a claim as it may first appear. The intuition I used to have was that string theory is making ridiculously specific claims about things that may remain always unobservable to humans. But the idea is not that experiments of unimaginable scale and complexity might reveal that the universe is made up of strings or something, it's just that it may turn out that string theory makes up such a rich and flexible family of theories that it could be tuned to the observed physics of some unimaginably advanced civilization. My impression is that string theory is not so flexible that its uninteresting though. There's some interesting theoretical work along these lines around exploring the swampland [1].

[0] https://en.wikipedia.org/wiki/String_theory_landscape

[1] https://en.wikipedia.org/wiki/Swampland_(physics)