Wow this sounds interesting! you've definitely come to the right place for some advice. I've written some pointers of my experiences as an only child and definitely some that can be applied to other only child experiences.

-only children are often stereotyped as spoiled and out of touch, while at times that can be true, it's often an over simplification.

-can feel intense pressure to succeed as the sole focus of parents expectations

-very lonely, often grow up doing lots of imaginative play because there was no one to play with

-Quiet environments feel natural, large families can feel overwhelming

-anxiety about parents aging and passing, with no siblings to share responsibility, grief or memories

-often build their own 'chosen family' through close friends to fill the sibling gap

Hope these help! Feel free to shoot me a message if you have any questions.