@AC - The fact that you used and liked their service
doesn't mean the service is legal. You can say the same thing about heroin for an example or about a paid killer.
Oh and by the way, instead all of the documents you mention while simply forgetting to add a commercial insurance to your list (you're forgiven), the authorities are simply asking for a taxi license which sums all of that. Nothing prevents Uber to ask for licenses for its drivers.
Please stop pushing Sillycon Valley smart BS on us.