The bar you asked for was "meaningful progress". And as you state, "both are very helpful metrics", it seems the bar is met to the degree it can be.

I don't think we will see a definitive test as we can't even precisely define it. Other than heuristic signals such as stated above, the only thing left is just observing performance in the real world. But I think the current progress as measured by "benchmarks" is terribly flawed.