Is having a sibling important?

paula
I only have 1 son his 6 yrs old . I come from a big family n I at least want one more for my son to at least have a brother or a sister but everyone tells me not to have another because its too hard out there . But then if I wait longer I'm afraid my son won't bond with his sibling or will be able to play with him/she. Is it really important for children to have at least one sibling?