"Looking out the window" and "steering the car" is pretty much exactly what current year cruise control systems do. Just go look at the Subaru Eyesight systems, which depend on cameras that face out the upper part of the windshield. https://www.subaru.com/engineering/eyesight.html

(Subaru's doesn't do active lanekeeping, but lots of other manufacturers like BMW and Ford do.)

The newer cruise controls have lane-keep assist and adaptive cruise control - you don't have to actively steer or brake. On an open road, there's effectively little difference from the Uber vehicle, which would also let you disengage autonomous mode by breaking or otherwise interacting with the controls. (The newest mass-market cruise controls are "stop and go", which means they'll even bring the car to a full stop, then start driving again.)