This is interesting. There's another implication here. That reliability/usefulness is an "emergent" phenomenon as underlying abilities become more accurate. It

This is interesting. There's another implication here. That reliability/usefulness is an "emergent" phenomenon as underlying abilities become more accurate. It's the difference between siri not understanding you 1 word out of 10 (very accurate!), and it basically just understanding you. It's a continuous accuracy function and a discontinuous usefulness function.