The technologist argument is: we are enduring losses, even large ones, in the short term so that we can bring inevitable future tools forward in time (i.e. "Of course everyone can get anything delivered on-demand in the future, so why not now!?")
The value-based investor argument: This is a gross subsidy to "tech" companies that is distorting/subsidizing markets and creating huge opportunity costs where all these billions could have been invested in better, even more fundamental technologies.
There is a third argument which is what's really giving these companies legs: they do genuinely have a lot of users who love the services. Who wouldn't want a VC-subsidized meal brought to your door?