Amazon was making real profits in each line of business shortly after entering - 1-2 years for books, music, etc. IIRC. They chose to reinvest that in further expansion but always had the option of halting expansion and being fully profitable if they wanted.

Uber has nothing remotely like that and, unlike Amazon, their costs scale linearly and their workers (who are most of the business) have no reason to be loyal.

Except that Amazon didn't have remotely close to the level of losses that Uber has. The year Amazon went public, they lost $30 million. Uber is losing a billion a quarter.

AWS lock-in is different from a taxi app. Only a few players so far managed to respond to AWS in scale and offerings.

Lots of taxi companies have their own apps at this point.

You’re saying cloud services is lower margin than retail? I don’t think that has ever been true.