I don't think age is the important thing here, I have worked with people of all ages (15-70 or so) that I look up to and learned a lot from. Experience is important, and it is hard to have experienced a lot of things if you are 20.
On a semi-related note, all my best bosses have been parents, having kids seem to teach you something about the value of time.
I once talked to an old (60) guy who was writing code down the aisle from me. He said he tried management, but didn't want to mediate disputes between children - he had his own at home. I thought his experience was probably unusual, but I've asked a number of managers since then, and they all agree that's an unfortunately large part of the job. I don't see it because they keep it away from the team - as it should be. But then when I got my first crack at "having a small team" I saw exactly the same thing. So yes, tech skills are important but parenting can also be a relevant background ;-)