As a monogamous person, my partner meets all my romantic/sexual/intimacy needs, yes. For other things, there are these things calls friendships, familial relationships, etc. Expecting a singular person to be everything to you isn’t monogamy, that’s more co-dependence imo
monogamous people are so weird to me. like you genuinely think one person is going to meet all your needs? or are you fine only having some of your needs met just so you dont have to be alone?