> it seems as if Uber’s losses were self-evidently sustainable.
With the unlimited free investor money. Same goes for the rest of "amazing starup innovators" of recent years (e.g. YCombinator's startups). The flow of money has now stopped/slowed, and we now see mass layoffs and a wave of bankrupcies.
Losing a billion dollars a year for 10 years is not a sustainable business. But somehow it has become the norm in IT.