The question should not be a choice between public transportation and owning your own vehicle.
Someone needs to detatch the passenger portion of the vehicle from the engine.
We like our personal space, and we want to be able to leave our belongings "in the car" while we're shopping or while we are at work.
But most people no longer care about the engine. It's just another black box they have to maintain.
Why can't the two be separated, in the same way that semi tractors have evolved from single component machines (engine firmly attached to the cargo carrying space) to dual-component machines, where any tractor can haul any trailer?
5 minutes before I leave the house, I call for a ride. I wander out to my driveway and get into my vehicle, an unpowered compartment. I have the optional self-directed engine for my vehicle sitting in the garage still, but I only use it for off-grid use, and this trip's strictly on-grid.
A moment later the small equivalent of a semi trailer arrives and docks with my unpowered vehicle. I programmed my destination into the computer while waiting for it to appear (or perhaps it's autoprogrammed, as I always leave for work at this time?) and all I need to do is hit the appropriate button to confirm that I'm ready to go.
I hit the button and slide back into my seat, wishing I was still in bed. Meanwhile, the automated, driverless tractor hauls my vehicle and me to work. It involves a pair of transfers -- my first tractor transfers my vehicle to a string of others towed behind a larger & stronger tractor before I enter the highway (woohoo!!! gotta love the reserved traffic fast lane!), and then I'm given back to a smaller tractor as I leave the highway -- but that happens entirely without input from me.
Twenty minutes after settling into my vehicle I'm getting out of it. My engine-less "vehicle" is sitting in my office parking lot, and the tractor's undocking from it so it can go serve another customer.