Whether to stand or hit on 16 depends on your judgment of the strength of the dealer’s hand. If the dealer’s upcard is strong, like a 9 or a 10, they may likely end up with 19 or 20. In this case, you may as well take the chance of hitting and receiving another card – you may get lucky and receive a four or five!
Conversely, if the dealer’s upcard is weak, like a 5 or a 6, they will likely go on to bust, so you can offer to stand in a broader choice of hands, including 16.