Yeah, and I do get it to some extent. Everything about having a child seems burdensome and hard. Turns out it's doesn't feel anything like that and I can't think of anything I'd rather be doing. I wouldn't swap with another person on this planet.
You got lucky and had kid(s) that were not extremely difficult to raise. Not everybody gets that. Not all kids are alike. Some will make your life a living hell. It is a total crapshoot.
Also, not everybody enjoys parenting, even if they have easy kids. We are not all built the same.
I did get lucky and had relatively easy kids. I love them. But, I do not enjoy parenting.
People can obviously make the opposite choice, but I'd encourage anyone that's never been around good little kids as an adult, to find a way to be around them in a helpful or fun role for a while. Volunteer at a youth group, sports camp, coding class, whatever. Or just be an "uncle" to some of your friends' kids. My volunteering at a church youth group in my early 20's probably gave me the nudge I needed.
I’d love to have had kids, but ew. That is creepy. When you’re a single man even just beyond 30, trying to be around other’s kids isn’t a good idea in today’s society. Besides, trying to play your part while the kid is in another education schema is inconvenient because any meaningful perspective on life might conflict with the parents’.
But probably my biggest concern with having kids of my own is that you can't really choose their personalities. Even the best parents can end up with kids who are frankly much less enjoyable to be around.
I love my kids and they're pretty great (and seem easy by comparison to others), but it's definitely burdensome and hard.