Cars, good or bad?

Of course they aren't.
Unless you have some splendid idea of how a disabled pensioner in a rural cottage is supposed to get to the hospital without one.

If and when cars become obsolete, they will be replaced by something an awful lot like cars.

Taxi? if the only car trip she needs to make is to the hospital, it'd be far more cost effective.

Most if not all Hospitals have some kind of community transport or run by other local charities/organisations either free or at a fraction of the cost of a taxi.