Humans are overwhelmingly social creatures by nature and virtually every study of happiness shows a correlation to healthy relationships in your life. There are exceptions of course, including people who have had traumatic experiences/abuse/PTSD/mental health issues that cause these relationships to be damaging until the underlying issue is resolved.

Humans are also very, very bad at knowing what makes them happy. If a healthy person tells me they have one friend they see once a month and no other social outlets and they wouldn't want anything else, 99% of the time I'm going to assume they don't know themselves well enough to know that more relationships than that would make them happy.