No they're not, and no they don't:
https://childmind.org/article/when-should-you-come-between-a-teenager-and-her-phone/
One of the basic rules of effective discipline is to make any punishment related to the misbehavior. “If your child violates curfew, taking away the phone is completely unrelated to that behavior,” says Dr. Peters. “You’re not connecting with the kid. You are making them feel bad, which you think is helping them learn, but in fact is helping them learn to be sneaky or learn that you are the punisher.”