Amazon has always been more like breakeven than profitable.
The difference with Amazon is that they would make a core business profitable and then use the free cash flow to invest in adjacent businesses. Users core business is not profitable yet.
Books->general merchandise->3p marketplace->prime->AWS->???
Where ??? Will probably be one of logistics, Alexa, or Whole Foods/Go/Fresh.
Uber is being criticized for having massive losses, which is much worse, because it means that they must make significant changes in the near future that will likely be detrimental to their growth and valuation.
Also, growth is more valuable for Amazon because they have a bigger moat.