It doesn’t matter what we think is right or wrong. If you deal with cash, you have to know the rules. If I go on vacation with a decent amount cash, I cary a receipt for it.
I agree that one has to manage to live with the oppressive laws.
But it is important to change laws that are wrong and oppressive. I did not realize that one needed proof the money is yours to travel. I often travel with 3-500 dollars. Wow.
I usually try to remember to bring a receipt if I am carrying over $500. It doesn’t seem like much, but you never know. Most of the forfeiture stories I’ve heard involve several thousand dollars or more.