Why theorize about "economies of scale won't help"? We know the answer is "yes they will" -- Uber's US operations were profitable in 1Q16[1] and that included many non-scaled markets.

Like I said 8 years ago[2]: "Facebook made ~$200mm in 2008. It's pretty clear they could profit on those revenues, and instead are choosing to invest in further growth (with outside capital)."

[1] https://skift.com/2016/12/21/uber-isnt-profitable-in-the-u-s... [2] https://news.ycombinator.com/item?id=427212