Caveat: this can potentially be dangerous. I used to go outside a lot when I felt bad, but it mostly let me stew in my bad feelings with nothing to permanently distract me from them. Now I always bring headphones to listen to music, because that’s a lot better at distracting me from the bad feelings.
You’re right that it’s your place to talk about your opinion, but you’re trying to deny them theirs, that’s the problem.
I find “powers” a strange word choice because of its connotation, but if you want to use it, whatever, language is a complex and subjective thing. Other than that, I didn’t see any generalization from the person you’re arguing with, so I don’t understand your response.
I think you might have misinterpreted their line about their giftedness, they said “I’m considered gifted” then explained that they don’t feel they have “powers”. This does not imply that’s the same for everyone considered gifted, so it is not a generalization.
I have some strategies I use for not getting into a situation like this. I try to assume the best from people, but when I think an uncharitable interpretation is likely I’ll ask clarifying questions like “are you saying that all gifted people are only good at IQ tests?”. Sometimes I focus on the wrong details, sometimes the other person says things in a weird way, clarification always helps.