Wazzupter I think having brother or sister is better because you can always rely on them and support each other, maybe you are messing sometime but it's pretty common thing and you will pass it trough for sure.
Also having brother or sister is cool because you can get advice from them or otherwise get advice from them , have fun and take care of each other

Being an only one child in the family has some advantages like getting all attention from your parents, also you don't have to share a lot of things with someone like your room or laptop. But I think the main disadvantages of being the only one child in family is loneless and boredom especially when you getting older.