My city only requires sidewalks depending on how much vehicular traffic, how much foot traffic, and if kids are expected to navigate that street to get to school. And even then "one side" doesn't mean "same side." My house and the one next to my neighbor have the unfortunate yards missing sidewalks, meaning people have to use my next-for neighbor's sidewalk, cross the street, use my neighbor's sidewalk, and then can continue down until they have to cross the street again because the sidewalk is unusable at a certain point.

The reasons we have missing and broken sidewalks are that:

1. The city won't help pay for them
2. The city has strict regulations on how they're installed
3. The 50-foot run of sidewalk would cost more than a car to install, and since they're often seen as insurance liabilities, it's practically impossible to get a reasonable loan to cover the up-front costs.

"My yard is the shitty impediment because I can't afford to fund a public service" is not one of the sad realities of home ownership that I expected to encounter.