Frustration not ever being the “main friend”

Does the frustration of not being the main friend happen to anyone else?

I’m friends with two other people and care about them deeply but I feel like they are always hanging out 1 on 1 without me and it makes me feel shitty. They always bring up what they did together or show me pictures and it makes me upset. Though I’d never tell them that. I really want to find one person to have a 1 on 1 friendship with. Someone I don’t need to feel sad about when they hang out with other people because I know I’m worth more to them.

Maybe what I want is more of a romantic relationship than a friendship, the exclusivity a romantic relationship has but without the romance. If that makes sense

I just want to feel important to someone. I’m tired of being a side character in every friendship I have. I just want to feel as loved as the other friend.