Amazon is definitely misleading: they became profitable within specific business areas (e.g. books & music first) but invested that money in new businesses. The analogy would be if, say, Uber was profitable in San Francisco and Los Angeles but still bootstrapping Phoenix and Denver.

I haven’t read anything which suggests they aren’t subsidizing rides in their most established markets just like everywhere else, and both their drivers and customers can switch to competitors so easily that it’s not obvious how they can change that.