Not in isolation. A 16 year old's upcoming expenses are a car, car insurance, tuition, housing, food, and more... And if possible should be contributing to a retirement account as well.

A 16 year old also may not have a college opportunity and may decide to go straight to work, may decide to go straight to having a family with a high school sweetheart. At that point, the 16-18 year old needs a liveable wage too.

No, 16-year-olds should not be contributing to retirement accounts. The return on investment in such an account will be far less than the return from investing that money in increasing their own human capital. This could be by buying good books to read, buying a computer to learn to program on, or paying for movie tickets to go out on a date with someone who may be their future spouse.