I see parents bring toddlers in trailers to grocery stores and farmers markets routinely these days. They make these big ebikes that can even haul kids directly without the trailer now and millennial parents have been buying them.
Lots of things could be, but removing cars from the average American's life will limit job opportunities, limit economic choices, and consume a lot more of our time.
It's not about removing cars, its about limiting them and choosing a more appropriate tool for the job. Sometimes you can get away with a hand trowel instead of an excavator.
Yes, but if you own a car, then you're already paying for something that can save you time and personal energy so you can do things you enjoy, like playing with your kids, or tending your garden. Often times the quickest and easiest tool to use is what you're going to reach for, and that's a car most of the time.
And the whole thing is that the personal convenience you get comes with great costs to every other facet of life when you account for the negative externalities that a car centric lifestyle brings. Now you have a bunch of black particulate on your window sills because everyone in your neighborhood has a heavy car that produces tire dust. Maybe you live a few years less on the whole because you a literally hardly moving around all day when all the walking you do is in your home or on the way to the car, when you could have been working in at least some time cardio wise riding a bike or merely being a pedestrian for all those decades. Often times for short trips on surface streets, like what would be a 10 minute car ride turns into a 12 minute bike ride or so, because stop lights eliminate all the advantages of a powerful car on city roads and perhaps effectively set the speed limit for everyone to like 15mph regardless of the signed speed. Four minutes a two way trip on the whole is not much time wasted away from your children or your crops.
For my commute to work, its something like my choice of a 35 minute drive (not counting the circling I will have to do finding a parking spot at the other end) or a 45 minute bike ride. I probably save time on the whole even without counting the parking fiasco, considering now I don't need to find time in my schedule to work in my cardio.