(And, as eru points out, they might be able to establish a regulatory moat to prevent any new entrants from arising once they're established, like the drug and medical device companies. Did you know the first clinical implantation of a cardiac pacemaker was in 01958, only two years after the transistor was invented? The patient died—in 02001, 43 years later. How long do you think it takes an incrementally improved new pacemaker design to get regulatory approval today? Much less a totally new kind of medical device?)

Keep in mind, though, that "VCs are betting" doesn't mean that the VCs think this is the most likely outcome, even the ones who did invest. It just means they think it's sufficiently plausible that if it does happen they want to own a piece of it.