It has delivered falsifiable postdictions though. Like, there are some measurable quantities which string theory says must be in a particular (though rather wide) finite range, and indeed the measured value is in that range. The value was measured to much greater precision than that range before it was shown that string theory implies the value being in that range though.

Uh, iirc . I don’t remember what value specifically. Some ratio of masses or something? Idr. And I certainly don’t know the calculation.