My family has a couple cars but we still ride with our kids in taxis all the time, for example to the airport or into/out of the city. Even hauling bikes isn't insurmountable -- we've taken weeklong bike camping trips with friends and because biking in a big circle isn't as much fun we hire a bigger vehicle that can haul a dozen bikes to the starting point.
> Just because they're driven by computers now isn't going to magically change all the reasons that people didn't use them before (hint: it wasn't because they were driven by humans).
Sort of. The primary reason I don't hire vehicles more often is cost, which is related to the human driver. The wealthiest families I know are much more likely to use a car service to ferry family members around.
If there was a car service that could whisk us to school, work, grocery shopping, etc with no more than 15 minutes advanced notice for less than the cumulative cost of a similarly-sized private vehicle I'd sell one of our cars in a heartbeat. I have no idea whether that future is years or decades away, but when it occurs many families I know would go from 2 or 3 cars down to 1.
I'll admit that going from 1 car to 0 cars would be a tougher sell. For that I'd have to be confident in five nines of availability and vehicles that can haul equipment like bikes and kayaks. But that doesn't seem like an insurmountable problem, just a logistical one that'll take a bit longer.