idk if any teenagers follow me, but I think something you should keep in mind is that when adults are criticizing teenagers as a demographic, it's like
50% them displacing their own self-hatred and regrets about their own decisions at your age, and trying to retroactively yell at themselves by yelling at you. they aren't thinking about you as a person at all. they are thinking of you as a symbol of "youth" in the context of their own life.
50% them trying to socially reproduce adultist superiority to soothe their own ego. especially if they start falling back on things like "your brain isn't developed (and that's why I'm right and you're wrong!)." adults confronted with a young person standing up to them in any context often become reactively insecure and reach for anything that lets them feel righteous about telling you to shut up, no matter how dubious the claim. they're just bullying you to boost themselves up. they're being an asshole.
adults will act like they know you better than you know yourself. they don't. so genuinely, before you internalize any criticism an adult says, remember that most adults are primarily talking to and about themselves when they talk about teens. it is annoying. it's not your fault.