Tips should not even be asked for or expected with such services. Uber should be paying fair compensation based on number of deliveries and distance travelled. The customer is already paying a subscription fee and sometimes a delivery fee over that.

I've heard that Uber subsidizes low tips to make sure orders get fulfilled if they're not accepted by a driver in a reasonable time frame. Theoreretically the tip goes up gradually the longer the order sits in the unaccepted pool (with Uber paying the difference relative to the tip offered by the customer). Part of why they do it is to take advantage of FOMO from the driver who knows that there are others who may accept a lower tip and will feel pressure to accept lower than they usually would. Almost like a type of auction.

Would be curious if someone who drives Uber could confirm that. Somehow people who tip $0 still get their food so there must be something to it.