If Uber wanted to be profitable, they could be tomorrow. Their growth would slow down, and they wouldn't be able to invest in next generation technology, but they could be a very profitable business.
Given the insanely high price elasticity of demand on rideshare, i severely doubt this. Show me anyone who does not have both uber and lyft apps, and does not immediately go to Lyft when uber prices seem a tad high (or vice-versa).
I’m in that situation. I know Lyft exists, of course, and will switch if Uber gets too aggressive on pricing, so your point has merit, but I literally don’t have the app nor account there yet.
OTOH, I believe Uber is already quite profitable in my city (Boston metro), so I don’t think a future of Uber as profitable overall is unachievable.