True, but not even that limited. Any individual that could benefit from not having to concern themselves with the outside environment. In addition to the senior citizens, you also have the handicapped, the makeup applicators, the cell phone users, limited eyesight drivers, the overall bad drivers, and more importantly, impaired drivers (alcohol especially).

Not just performance in terms of efficient driving and merging, but also safety and essentially taking human operator error out of the equation (for the most part)

Surely not as much as widespread delivery services? Of course the delivery services could use self driving cars, to make them as cheap as they were 50 years ago when almost all shops delivered.

Just because cars made suburbia possible still does not mean it is a good thing.

When they are mainstream and people are comfortable with the idea, it will start filtering down to use by kids. Then we'll see the reinvention of suburbia and even deeper changes in the culture and the fabric of society.