What you're missing is: today, we're nearing the point where actual general purpose robots become viable.
Which means: the purpose of a robot is no longer to sit at a factory line and precisely execute the same exact motions on repeat 24/7. The purpose of the next generation of robots is to learn generalized behaviors, adapt to circumstances, and carry out circumstance-specific actions with active sensor feedback. Which means completely different requirements for effectors.
Which means: repeatability can go get fucked, for one.
