Teen stalling is often not stalling at all. Many teens are biologically awake at the times families are trying to put them to bed. The natural sleep window for adolescents has shifted later due to the circadian phase delay of puberty, and this is independent of screen use and habits, though those compound it. Demanding sleep before the biological window is like asking an adult to fall asleep at 7pm: possible with effort but working against the body.
I am not going to fight your biology. I do want us to protect your sleep. What does a realistic wind-down look like for you?