I think it car ownership will go down - but what if you want to go to the mountains or beach with the kids, or pickup several pieces of lumber and paint at Home Depot, or other bulky items. It gets pretty expensive to rent a car or use something like Car-to-Go if you want to go hiking or mt. biking.
I live 4 miles from Home Depot. I bike there for lumber and paint. The only time I ever rent a truck or trailer is when I need lots of really big stuff, like 20 sheets of plywood or 1000 lbs of flooring. And let's be honest, I'm not about to fit that stuff in a normal car; I'd be renting or borrowing a truck for that stuff either way. I also live in a hilly city (Seattle), with no e-assist on my bike. Throw in an e-assist or consider a flatter city, and HD runs would be downright easy for most people with a bike, given safe/inviting routes.
8ft long grounding rods and trim? Not a problem. I recently carried some 10ft long PVC conduit for replacing my meter base, but I can't find pics of it. Same setup, though.
400sf of cork underlayment (around 50 lbs each)? Again, not a problem.
Random paint, drywall mud, and other stuff? Easy. Best part is, at big box stores you can just take a bike in with you and use it instead of a shopping cart. Much nicer than having to transfer stuff between your shopping cart and your car later on.
Those boxes are filled with 150 lbs of metal and leather stools. In hindsight they were a mistake (cat claws + leather = fail), but at least they kinda look nice.
It's so easy hauling this stuff on a bike. Often I won't even bother with the proper cargo bike and I'll just use my regular road bike. A can of paint or a bag of joint compound is no problem with a decent rack and pannier system.