Earlier quoted context omitted.
If the "waste" is subsidizing services you actually want, is it really waste? It's more of a transfer from investors to landlords and drivers, who certainly wouldn't be as happy with less money.
I think the "waste" aspect of it comes from the crowding-out effect of capital allocation. Large sums going into the on-demand economy businesses means that there's far less available to invest in other types of business models. That in turn may incentivize some businesses to "pivot" to an on-demand model purely to get their foot in the door with some investors, regardless of whether it makes business sense. Remember…
Compare with a boom-bust cyclical model where boom times make raising money easier for everyone. Under this model, overly enthusiastic investors eventually get discouraged after losing a lot of money, so the amount of investment money available changes a lot and thinking of it as zero-sum doesn't really work.