I'm betting yield per robot for lower error rate rises, but when bad programming hits, yield per robot hits the floor and we get swamped with product failure down the track.

Highly repeatable acts on a circuit board or assembly become deeply ingrained into the product. Having a loose bond on two phones because a worker sneezed, vs having 140,000 trash in a year because a 1G placement force was 0.1G out of whack...