Semantics. Cars don’t cost that much to operate. Uber doesn’t cost that much. The portion going to the human take home pay minus car value depreciation and other expenses is small, but a substantial chunk of it.
Right now, all of these are fully on the drivers. This will turn around if Uber rolls self-driving cars worldwide.
Uber wouldn't work if they owned the fleet - it's a huge advantage to just be the app + ops + acquisition costs