They are all driven by the service margin. Today Tesla margin is only 16-19% as a car company, if they want to be a $3T or $5T company, they must have a product with 30% margin at minimal.
So, I dont see Tesla giving up rideshare service easily and give it to UBER.
This is why Elon always wants to license Tesla Software to other car OEMs (let them keep low margin car making business), but has not engaged UBER talk aggressively
But Uber does have customer base. So we will have to see how much better Tesla can offer and whether this is a brand new market they are creating, or just the same old (in which case Uber will win)