Do you just invent stuff to dramatise your own narrative?
Because that's a spectacular load of bull to create from: Most only children would prefer siblings in both younger and later years. This thread shows that. My personal experience is aligned with this. The parents of only children are very insistent that their children prefer this, very vocal about how their child absolutely loves it. The majority of only children on this thread beg to differ.
I had dogs, cats, ponies. Endless holidays. Clubs. Activities. Over compensation in other words. They thought they were giving me the world. I'd have swapped the lot for someone to grow up with. I had five cousins in walking distance. It's not the same.
I imagine most children would have looked at me and thought how insanely lucky I was (v. wealthy parents) with all my "stuff" and constant experiences. And yes, it looked like that from the outside. But I wanted to wake up every morning with my sister and creep downstairs. To share secrets. To have a brother to jump out of trees with. To just have someone there to play one bloody board game with without it being a parent or an arranged play date. I would yearn for school holidays to be over, just so I had my friends back. No, playing out often isn't the same. You can't imagine the boredom.
And that's not even the most difficult part. Teen to adulthood as an only, is hard. No sibling to confide in. No sibling to ask for help. My cousins are all siblings and they socialise weekly, at each others, at their parents. Holidays, Christmases, always out together. Childcare. They have nieces and nephews, they are aunts and uncles. They are the proverbial "village" raising their own families. Me? I'm on my own. My parents are in old age. To care for. To worry about. To run after. When they pass it will all be on my shoulders. I'll inherit a fuck tonne. I won't have to share it. Woopy doo.
And my parents will be the first to tell you how charmed and wonderful my childhood was. Couldn't have been a happier child, who wanted for nothing. Oh, but wait, I can't "prove" them wrong, so it must be true...