I think anyone without children will always say there are no cons to not having them, because they haven't experienced the other side.
Experiences of what they see with friends and family members with children, is not and can never be the same as having your own children.
I have children and I have no cons. For those who have children that have brought stress to them, made poor life choices, have health conditions that unfortunately impact on the family, are uncaring, ungrateful, unappreciative, rude, get into trouble and criminal activity, then of course they may well see the negatives and regret having children.
I see finances mentioned as a con, but surely you know kids will cost. It's not a surprise that a child who goes to University will require financial support. I personally don't see this as a con, because I'm proud to have DC in University and we can afford it, because we planned up for it. Of course I'd have more money if I didn't have kids, but money isn't everything in life.
The biggest thing that irritates me about these threads, is those without kids making out that people with kids have been restricted in their enjoyment of life because they have kids. That they can't go on holidays, or nights out and that they live in poverty because of the cost of kids.
I have kids and my enjoyment of life hasn't been limited as a result. I've travelled and gone on holidays with and without them...usually twice a year. There's nothing I haven’t been able to do because I have children.
My SIL is childfree. She lives a good life and seems happy enough. I don't see any regret that she doesn't have children. I don't see her life as better or worse than mine. It's just different.
I very much doubt that when a couple get together to have kids, they think, great, here's one to look after me when I get old. You don't have kids for the sole purpose of looking after you in old age, but that may happen naturally and depending on cultural background, it would be a given.
Having child or choosing to be childfree is a choice. Make your choice and be happy with it.