[krastanov]

We are talking past each other: It is a bit contradictory to say "quantum computing is up in the air" and "QM is one of the most tested theories" as an argument against what I am saying. Yes, both are statements are true, but they are in no ways counterpoints to what I am saying, if anything they support it. QM is a well established and empirically tested theory. Quantum Computing is a purely mathematical construct that emerged from that well established theory without any experimental evidence for it, and only now, 30 years later, we are starting to have a chance to employ this purely mathematical construct in practice.

Same with GR: it was a purely mathematical construct for a while until we could test it, but there were too many theory clues that it must be right.

And this is not selection/survival bias: it is extremely rare for humanity to find a robust mathematical construct for which we can have a high degree of certainty that it describes the universe well. In the few cases where we have had that certainty, due to mathematical proofs in seemingly disjoint fields, we ended up being right.

To push it to stuff like super strings and quantum gravity: few respected scientists would claim that their pet mathematical construct is correct, but many of them will say "the vague commonalities between all these diverse and seemingly unrelated mathematical constructs definitely point to an underlying fundamental construct".