Speaking from my past experience it is very difficult to find good friends. Some friends are shy and not really the social type so you should make their life easy by helping them improve their social skills. That's why friendship is the most important thing in our lives.
Not all people are good so you should be careful on who to make friends with. The good thing about friendship is that you are not always alone. You feel like you have someone who cares about you. Another good thing is that when you get to know more about them you get to the interesting part where they talk about their home life you feel like you want to know how they act at home. The bad things that affect them is that they sometimes don't trust you. They can sometimes also break promises. For example, you have a secret diary and your friends find out. They start reading it and tell everyone your secrets. You feel like you don't trust them anymore. That's the bad value about friendship.
I have a few close friends and they actually care about me. I feel like I have someone I trust. We never ever fight. Whenever I have a big secret that I don't want to share with everyone I feel like if I tell them they won't understand and I'll lose trust with them. But always when I have a problem I always tell them about it. I feel much better after I tell them because my problems are going to be solved and I don't have to deal with them anymore.
Sometimes things go wrong in friendships. We sometimes have some childish arguments. And sometimes they're not very good because there's something going on that they're not telling you and they lie to you about it. Sometimes problems are not always solved. It's like in marriage and divorce. There are also some problems that occur in friendship. Maybe some of them are bad so you can't hang out with them anymore and maybe some I don't know have problems and that you can't be together anymore so you have to break up. When you lose friends now you feel lonely and don't have anyone but your family. So that's why it is difficult to find good friendship.
Good friends don't always have to be the same age as you. My sisters are not just my sisters but also my friends. Even my cousins I feel like I'm close to them. Some people lose contact with their friends as they grow older which is a sad way to lose a good friend.
I think friendship is the most important thing in life because if you have no friends you have no happiness and you'll not trust anyone but yourself.