That's dependent on your definition of integrated. Uber drivers never go into Uber's offices. They never meet Uber staff or managers (the actual employees of Uber). That's possibly as far from "integrated" as you can get. Uber drivers have a very similar relationship to Uber as it's customers do -- but you wouldn't argue the customers are integrated.

They may be essential for Uber's business but that is different. Customers are also essential. Contractors can be essential.