[rtempaccount1]

The problem with Uber et al, is not that they cannot become profitable, but that they cannot become sufficiently profitable to justify their valuations.

Uber has burned through many billions of investor cash. To show a reasonable return on that cash it would need to generate not just profit, but a lot of it.

Whether it can do that in markets like taxi's and food delivery is a quite debatable point as competitors will continue to spring up quickly especially when Uber tries to put the prices up enough to generate the kind of profts needed at their scale.