I am not sure if friends replace (at least my experience of) cousins. With couisins, you spend days, nights, sleepovers sometimes a whole summer together. You share grandparents, your parents are siblings - you never leave each other's side. It's like sibling minus one. With friends, yes you get very good friends and they are your "chosen family" but you don't spend half as much time together even to the best of your efforts (unless living next door) at the same time, things force you to fall apart - moving, schools, preferences etc.