engagements and marriage

My friend just got married and it made me think about my relationship. I've talked about marriage with my bf and he says that he wouldn't want to get married because he doesn't want to make that commitment so young but I said well we're already planning on being together forever why not just get married.i didn't want to push it but it kinda just got to me right now that I saw my friends photos. She's also 22, been with her boyfriend for two years and it just made me insecure about my relationship. Idk why I let it get to me. I know we're young. But why not?