Amazon has not spent years losing money, they merely chose to match spending with revenue so their numbers were balanced. That's quite different to winning market share through raw subsidies.

Key distinction. As well as assembling an incredible logistics system. Uber has... a trivial app that's already been cloned dozens of times?

Uber's saving grace, if it will ever get one, will be autonomous vehicles. First the technology has to get good enough, then the law has to catch up. All while Uber is just dumping cash to fend off the aforementioned dozens of clones by artificially deflating their prices?

My bet is that they'll run out of time/money.

Their paid in capital is greater than retained earnings. Which basically means profits are less than what the share holders have put in.

Amazon actually moves product, and there is a HUGE infrastructure barrier to entry in the AWS space.

Uber competitors don't have either of those stumbling blocks.