If the rules were actually that simple, the world would need far fewer lawyers.
But - whether you say "rules that simple can't work when the world is vastly more complex", or "rules-writing lawyers aren't stupid enough to write their own kind out of their jobs" - the rules are definitely not that simple.
Simple rules aren't very feasible though, laws need to be well defined and the sheer scale of societies today makes that anything but simple.
I'd argue that's the main reason for not making a law though, if it's too complicated for the average person to read and understand where the line is drawn then we shouldn't draw it.
If the rules were actually that simple, the world would need far fewer lawyers.
But - whether you say "rules that simple can't work when the world is vastly more complex", or "rules-writing lawyers aren't stupid enough to write their own kind out of their jobs" - the rules are definitely not that simple.