I actually feel similarly (though not slice of life stuff; I'm really not into those); it's getting kind of annoying that most characters are teenagers. I'm not saying I need to see a character pay his taxes or go to his office job, but adults don't think or act like teenagers, and you can have characters who are married with kids (I don't think I know of any anime with a protagonist who's an adult, married and has kids). The story dynamic is just different.