There's plenty of laws they write that they know the population can't reasonably comply with and give the government discretionary power to screw people. And then there's more laws that just give the government enforcement arm discretionary power to choose whether the law is applicable or exercise unilateral judgement regarding whether compliance is satisfactory.

Your local zoning code is probably chock full of them. And if not there then your local stormwater/runoff rules probably have a bunch of examples too.

Federal stuff is much more highly litigated so you don't see as much of it there. State is a middle ground.