1. Uber switched to delivering multiple orders per driver trip and then charging extra if you wanted priority. I imagine this would've helped their unit economics immensely and allowed drivers to make more money.
2. Deliveroo had a functioning customer service who would often refund orders and give discounts in order to deliver a great experience. Uber deliberately didn't. No support = more profit.
3. Uber would charge multiple tiers of fees. Service fee. Delivery fee. Eventually they were charging twice as much on top of the order as Deliveroo and it took a while for them to do the same.
And then Uber One subscription likely did them in the end. The ability to save on both home delivery and trips was pretty compelling.