Can someone point out where "powered rollerskates" are strictly worse than legs in civilized urban human environments, to an extent that a few extra hundred billion dollars of R&D are warranted? The "approximate capabilities" of a human are: moving around, and picking things up / fine manipulation. Wheels + arms does that just fine, and eliminates a lot of power, complexity, fragility. And it also potentially adds.
This is one of those 80/20 things that is just glaringly obvious. Like lvl 5 autonomous cars vs lvl 3-4.