While I entirely agree in principle with the idea that laws cannot solve all problems, I must disagree that we should aim for a society where any one person can understand all the laws.
Our society is extremely complex. There are many many industries and activities that need to be individually regulated. Let's take a few examples of very specific, arcane laws that are important for everyday people who might not even know about them.
1.
Suppose you buy a home, and in the bathroom, there is an exhaust fan. You use that fan for years, and one day discover that it has been venting into your attic, and that your attic is thus absolutely full of toxic mold that will cost a small fortune to remove. And if you don't remove it, you're endangering your health and possibly making your house unsellable.
As it turns out, most jurisdictions in the US require, by way of the building code, that bathroom exhaust fans be vented directly outside. Had that law been in place in your jurisdiction, perhaps you wouldn't have a mold problem today.
2.
Now imagine the FTC doesn't exist, or perhaps that its regulations are vastly simplified. You have a pension plan. You don't pay much attention to how your pension fund is invested. One day, you see on the news that your pension fund has dropped in value by 50%. It turns out the plan was heavily invested in a certain company that looked good in its prospectus but was actually in very bad shape.
If today's FTC existed, with its complex and obscure regulations on how a company must report its financial state, perhaps your pension fund managers would have been able to make a better decision.
3.
Now suppose you rent an apartment. Your landlord turns the heat way down for no apparent reason, and it's 50 degrees in your unit all the time.
In many jurisdictions, there are laws requiring landlords to provide a minimum level of heating. With such a law in place, you could force the landlord to turn the heat back up.
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Each of these examples hinges on a law that most people will probably never think about. Yet you may indeed benefit from them many times in your life, without ever knowing it.
It could also be argued that such laws are not guaranteed to prevent the negative outcomes imagined above. This is true. No law will be obeyed 100% of the time. But that doesn't make them useless. Laws can and do influence behavior--when they come with an adequate enforcement mechanism, that is.