Self-driving cars may help with the actual weakness of transit, which is the long tail of trips. Trips on routes with too few passengers to justify good transit service, and with the trips too long for the last-mile solutions.
I'm not saying self driving cars are the solution, but they are a piece of the solution.
With furniture, you usually pay for delivery. Especially because the furniture store probably doesn't have the items you bought on site anyway.
Cars are a piece of the transportation puzzle, but groceries and babies aren't why they're needed.
If people aren’t spending $12k a year[1] to own a car, paying $50-150 to have a large piece of furniture delivered isn’t a big deal.
When there is well maintained, pedestrian friendly infrastructure, instead of a tiny uneven sidewalk inches away from 45 mph traffic, pushing your baby stroller home is not an issue.
[1] https://www.bts.gov/content/average-cost-owning-and-operatin...