I think I got bingo'd
Yesterday I talked to my social worker about this subreddit and being childfree myself.
She told me I shouldn't say that "I never gonna have children." or "I never want kids." because I can't look into the future and it gives other people the chance to respond with something invalidating. I should rather say: "I can't imagine having children." or "I don't want children now".
We often discuss how we communicate and how we can get better at it. So I know her intention wasn't to invalidate me, which she did anyway, ironically.
In general I would agree with her, because we can't really look into the future, but not with such big life choices like kids, especially when you have multiple reasons not to want/have children. She also knows that I want to get sterilised, which sounds even more stupid to say that I don't want children now.
And I think it still gives people chances to respond and invalidate. People that want to argue or want to convince you to have children will always find something to respond, no matter how you communicate.
The worst thing people could tell me if I would say: "I don't want children now." is "oh, it's good that you wait until you're ready." or something like that. Because it completely misrepresents and denies the reality of me being childfree.
Anyways, I just needed to write that down to process it. It's fascinating and frustrating at the same time how some people think and respond to the world.