No age really defines annoying. I've run into some cool little kids and also very annoying ones. Same goes for teens and advlts. Mute function is your friend. Although does anyone ever notice in games people yell shut up instead of just muting? It's almost like they enjoy being angry or something.
No age defines annoying. I have some friends who are younger because they are the annnoying ones that spam useless information all the time. Also I know some older people who don't curse and talk like they're drunk like a lot of randoms do. Just saying.
Jeez, way to judge. Just because someone is a young kid doesn't mean they'll be annoying. Some player are annoying, some of them are kids, some of them aren't. What platform do you play?