Motors have been used to a far greater extent than some U23 Belgian in 2016.I don’t need to look into it. I’ve seen enough on this subject.
I'll note that before that, there was a resounding harumph from many that batteries were not strong enough, and small motors were not strong enough, and small motors wouldn't do enough. If one cares to look, one can find significant evidence that the technology has always been ahead of what we believed existed.