Plenty of people have voiced much larger visions, for decades. There was a spate of futurists in the 80s, Waymo itself, and others like Dave Ferguson of Nuro. But autonomous vehicles have been an incredibly volatile industry. Anyone shooting for the moon (that's not seemingly immune to market pressures) has had those grand visions beaten down by the whiplash of funding. Companies have responded by focusing on those those first, real steps to demonstrate the "easy" stuff. The experimental stuff will come later when they're looking for ways to expand and investor money is more confident in the technology's future.