Not only am I an only child, but I'm an only child with two only children for parents, so my family is very small. Which means I don't have too many allies within my family other than my grandparents and parents. Which, during a divorce can be pretty hard in terms of who to lean on. The one thing I had wished for during this time of my life was to have a sibling who could go through it with me. Most people think being an only child seems amazing. You get all the love, attention, money, gifts, etc. But it is not these things.
Yes, I got attention, but I got so much of it to the point where now in my adult life I crave that kind of constant, undivided attention that people simply do not give you. Of course, being the center of attention in your family was great as a child, but it can also be a lot of pressure. Being a golden-child is not an easy thing to live up to; in fact, it's almost impossible.
Being an only child is also very lonely. Lonely because there is a part of you that craves being alone because you became so used to it, but also lonely because there's no one in your family who relates to you on a close level. My mom and I are best friends, basically sisters, but ultimately she is still my mom. When she had to parent me often times (mostly in my teenage years) it would cause a strain because it is hard to be parented by someone who you are that close with (and when you're a bratty teenager).
People also typically have bad connotations of only children. We're spoiled brats who never learned the lessons that having siblings teaches you. While the second part may be true, we also learned lessons that having siblings can't teach you. And we are certainly not all spoiled brats. I was admittedly very spoiled as a kid, but I was not a brat for it. Being literally the only grandkid, the only person to spoil by everyone in the family, it is easy to understand why I would be.
So before you walk around deciding that being an only child is the way to go, just remember that it's not as easy as you think. It's very different than having siblings, and not only in good ways. Be thankful for your brothers and sisters, because there's a kid out there wishing that they had one (only sometimes though, let's not get too crazy).