Lots of game developers started off as hobbyist modders when they were young. Maybe they’re trying to eliminate the future competition. More likely, Denuvo’s actual primary purpose is DRM and anti-cheat is just how it’s sold to players.
I think you have an overly optimistic view of the world.
Yup, that’s a great way to start a marriage. “I love you with all my heart and want to be with you forever. Also, I don’t trust you, so let’s get a prenup.”
The law needs to protect people by default. It’s just impractical not to. You have to keep in mind that humans are not perfect rational agents.
Plus, if it did work the way it was supposed to, there would be zero harm done.