In-Car Experience is Simple, It’s 2nd & 3rd Generation Impacts That Are Wild
You are correct that we want fully autonomous vehicles and not semi-autonomous cars with drivers “supervising.”
As you say, media companies are salivating over access to this extra time. But, unless your life is radically less overloaded and time-starved than mine, there is no shortage of things to do with the extra time with self-driving vehicles.
Thus, setting aside delivery services, seems to me that self-driving cars wind up being simply the equivalent of another room of the home or the office, or a party venue. Consequently, the additional in car time is likely to reflect essentially the same activity ratio we already see.
However, like most major lifestyle innovations, it is the second and third generation versions that are really consequential. In this respect, urban environments, meaning of commuting and distance travel are likely experience the biggest impacts.
My Medium publication, A Passion to Evolve, has a article you may want to read entitled, Doc ‘s -Next Gen Self-Driving Vehicles & Flying Cars