That's because it's cheaper to settle than to be compliant as a result of prosecutors willing to settle for a fraction of what would otherwise be dueThat's likely true, although I think the dominant factor is probably the laxity of enforcement. That is, even if the penalties far exceeded the cost of compliance, if your chances of being caught are small enough, the economics (if not the morality) favor noncompliance. There is also the problem that attempting to be compliant can call attention to your noncompliance, thus perversely increasing that chances that you will be penalized.
Anyway, in most civilised world the opposite is true. Non-compliance can be VERY costly.
In my mind what is worse about the current US system is that once one accepts the existence of contradictory regulatory regimes combined with lax selective enforcement, most of leverage that would keep the system sane is lost. If the penalties are severe and regularly enforced, there is a much stronger feedback to make full compliance efficient, or at least possible.
I'd rather have the piece of mind knowing that I'm compliant.
While it may provide peace of mind, realize that there is almost no way to know all the rules, and you are almost definitely noncompliant with regard to some of those you do not know. There are likely agencies that believe they have jurisdiction over you that you've never even heard of.
In my case of running a vegan frozen dessert business in California, while my research had revealed that the California Dairy Board reserved the right to regulate non-dairy frozen desserts (under the theory that a consumer might be confused into thinking that they were a dairy product) I was surprised when the federal Food and Drug Administration found me noncompliant for failing to properly register under the theory that since we had purchased some of our ingredients from another state (cocoa powder) we were engaged in interstate commerce and thus subject to their regulatory burden. While we ended up not paying any fines, and while the agents involved were polite and respectful, there were several painful days wasted on record searches and interviews with all of our key employees.