Former Google Xer here. Yes, "they just... have too much money and are over engineering something because they can". But also they are trying to fly precisely

Former Google Xer here. Yes, "they just... have too much money and are over engineering something because they can". But also they are trying to fly precisely through extremely busy and regulated airspace to make a pin-point delivery of a low margin product. So you really do need a hover-capable vehicle and a method of landing within ~1m of your target. This may or may not actually be a good business model, but as you point out, in fancy countries we already have roads and plentiful hospitals. Zipline's drop zones are larger and their operating area is so rural (not even roads! let alone air traffic!) that they had the freedom to choose simple, reliable design strategies.