As a non string theorist my understanding was that string theory actually makes quite a lot of empirically verifiable statements, just that those statements are only interesting at either never or extremely high energies.
I think ppl are asuming that sting theory comes from the meme about turning 1+1 = 2 into some massive integro differential equation. The world is rarely so simple.
I’ve heard that it also predicts at very low precision, some values that are practically measurable, and, unsurprisingly for how little precision these predictions have, these predictions are correct (I.e. the experimental results are within the predicted range).
(Or, maybe “a prediction” rather than “predictions”? I only heard about one, and I forget what it was.)