Properly torqued screws do not loosen.
That certainly is an engineer's answer.
No disrespect intended, but as a 45 yr long mechanic, I'd say the world doesn't work that way. If it were the case, you'd never, ever see Nyloc fasteners, safety wired fasteners, 15 dozen different styles of lock washers, leventy seven different formulations of LocTite, etc.
Yes, every fastener has a proper torque. And having the fastener at that torque will pretty much guarantee that as long as the engineers did their job properly, you'll end up with the clamping force you were trying to achieve. But it is not now, and never has been, a guarantee that said fastener won't vibrate loose without something to prevent that from happening. It all depends on the materials used, and the application they are used in on a case basis.