I think that's a False dichotomy.
I am an Ambivert on the exact middle of the two extremes, the vast majority of my friends are, and I'm interested in another Ambiverted/moderately outgoing person.
When it comes to introverts, I do get along with them quite well, but I dislike the fact they are homebodies.
Whenever I spend time with introverted friends, they just want to sit around the house the entire time I'm there while I'm bored stiff. I am the one who has to make the effort to plan and undertake outings, and it's exhausting that all the responsibility is placed onto me. It's either I sit around the house with them, they are happy with this and I am not, or go through the exhausting effort of organizing outings just so I can have fun with them.
Also, most of my introverted friends rely on me to get them out of their comfort zones and help them be more outgoing and social, because they can't seem to help themselves.
Introverted friends are great to talk to, very understanding and insightful, at the cost of being dependent on me to be the source of their outgoing, adventurous fun.
They know I'm more outgoing and social, and that's what my role is to them in a friendship - the outgoing, 'fun' friend who can possibly introduce them to new people, etc.
But I don't enjoy it.
I like ambiverted friends - they are more low maintainence and don't require as much work, because they are just as interested in getting out of the house as I am.
I can barely be friends with introverts, I don't honestly think I could date one, unless she's willing enough to get out of her comfort zone so that she doesn't rely on my extra help to do it for her.
Extroverts are also relatively low-maintainance, except they want to hang out and speak more often and it's a little exhausting, but they're more understanding and know I'm not an extravert like them but an ambivert.