Newtonian mechanics also was a well established theory with multiple confirmations, but that did not mean the predictions it made were exact.
Shor's algorithm working for large numbers would rule out some of interpretations of quantum mechanics like objective collapse, something that have not happened yet.
In any case my argument was not about any particular interpretation of quantum mechanics, my argument is that building quantum computer allows us to test our understanding of physics in conditions where it have not been tested yet. And so even if that did not produce any additional benefits the testing itself would be worthwhile.
Shor's algorithm working for large numbers would rule out some of interpretations of quantum mechanics like objective collapse, something that have not happened yet.
In any case my argument was not about any particular interpretation of quantum mechanics, my argument is that building quantum computer allows us to test our understanding of physics in conditions where it have not been tested yet. And so even if that did not produce any additional benefits the testing itself would be worthwhile.