They can, but unclear how good the margins are, if manufacturing becomes commoditized since so many players are investing in it. Lions share of profit will likely go to whomever owns the customer relationship w consumers
Also arguably the company providing the contact with the customer is more of a commodity. Certainly its the easiest aspect to replace. 100 companies could handle that tomorrow with existing tech for example. I can imagine people using a service that shops a bunch of car services and lets you connect with any of them.