I’ve not read the link but I have an only child (not by choice)
I’m from a family of 4 kids, none of which are in contact with each other as adults.
My sister was born just 13 months after me and I’ve never bonded with my mother. My sister was a needy child with some issues and learned very quickly how to manipulate and control our mother for her own attention.
This continued on into adulthood, living like a parasite back home until she was 38 and letting them bring up her daughter until she was 15, not paying a penny and causing mess, filth and stress.
She has now gone but I’ll never forgive my patents for allowing her to ostracise the rest of the family buy hogging the family home and parents for everything financial and childcare and emotional support.
Because of the feelings I had of being detached from my own family I desperately wanted my own children to form a close knit family group with but I couldn’t conceive any more and I have struggled with it tbh.
The worst times of year for me having an only is Christmas and summer holidays abroad where you’re surrounded by big families and kids playing together.
My dh on the other hand is an only child and has always had a close and very positive relationship with his parents. They’ve been fantastic for giving us help when we’ve needed it whereas my parents had 3 other families to help.
Overall though, now my only is a teenager I’m happy I only had him as he hadn’t been an easy child and I don’t think I’d have coped with any more when I think back. Regardless of how he turns out I can honestly say I’ll be there for him without being played by his siblings if he’d had any.