Why do so many people comment on things not asking for their opinion?

I’ve seen to many times on this sub (not saying this is the only place I’ve seen this, but I see it a lot here). Questions will ask things like “Have you ever been/done/experienced…” where the OP clearly wants to hear previous experiences and people will just answer with the “No” or “I haven’t.” What’s the point? Most recently someone asked the opinion of moms, specifically, and so many childfree people answered about why they wouldn’t have kids. There are many questions on this sub, constantly, asking for opinions from both sides. There are plenty of opportunities to share your opinion. But why do so many people have to comment when it’s been made clear their opinion isn’t the perspective thats wanted? What do you get out of it? And I’m not mad, just baffled. As a mom, I would never comment on a childfree post because that’s not the perspective I bring and that’s not what’s wanted.

Just looking to understand more about why this happens. 🤷🏽‍♀️ nothing serious.