No. I only have one, mostly for medical reasons. (My doctors didn't say I couldn't, just I probably shouldn't.) But really, it turned out to be right for my personality. I found out that even with just DS and DH, I feel guilty when they both need my time and I have to choose. If I had several children, I'd probably feel that way all the time and be miserable. I'm also very much an introvert - I recharge in the quiet, slow times - and with just the three of us, I can usually find enough of those. And I will say Disney trips are easier.
There have been a few times over the years that DS has wished he always had someone to play with, but there have also been times when he has come home from friends' houses grateful not to have younger siblings "messing things up". We've been open about both the positives and negatives of being an only child with him, and tried to lead him to concentrate on the positives. It also helps that we live near his cousins, so he has those shared memories of family holidays and such with people in his own generation.