With two kids aged 10 and 12, I need access to a sports park for practices and games. I need space to park a car and roads wide enough to support them because I have a lot of things to haul. I need good public schools that don't break the bank to provide my kids the support and community they need.
Everything smooth and convenient about living as a single person in an urban area quickly turns into living life on Hard Mode for families. As our working adult population ages, cities need to evolve to meet these needs, or expect people to move out as they outgrow the lifestyle.
I'm sure there are folks who live in places like SF with families and ride around in heavy urban traffic with 2 kids on an electric cargo bike, but that's just not for many of us. We're happier and way more stress free in the suburbs or even in the rural areas working remotely.