I've been following quantum computing since D-Wave made its press release some years back. Now I'm a complete skeptic.

The huge red flag I can't get over is if it is as so, why can no one validate it after all this time?

Why is there the proverbial "it works but not in the way you think it works" (i.e., quantum annealing) or "it works but we can use non-QM systems to simulate it faster, better, cheaper by a factor of a trillion"?

If QM computing was truly feasible (assuming that QM does have an underlining phenomena that is physically real), why are the results after all this time so fuzzy?