You're not wrong about OP's confusion, but a quick note that uber recently reported quarterly revenue of ~3.1bn which means "tens of billions" annually is exaggerating a little.
Does uber count it's fees as revenue or does it count fees and the fares (which get passed back to the drivers) as revenue?
My opinionated take is that if uber wants to pretend that drivers are not employees and it's just a marketplace then they shouldn't be booking the fare as revenue, just their cut but I'm not an accountant and I don't make the rules.
