Anything that requires any level of endurance or 'number of plays' no matter how hard are still in the realms of possibility for anyone.
My only concern with the endurance ones is the tedium. I'm playing every daily every day-- it'll still be over a year before I get my Who Am I Mastery? badge, and because I don't really like that game I've always considered it a daily chore.
A lot of online role-playing games have dailies as well, completed by a niche fanbase looking for justified rewards at the end. Of course, due to constant reinvention and expansion, those rewards are usually trumped by bigger, better things which always made me ponder the 'why?' of the whole thing.
FunTrivia's not really like that. We don't retire too many badges; you play, as normal, and win. The thing with the dailies, however, is that I don't feel I have a choice but to play certain games I don't care for (WAI being my main example, but some days that Pot of Gold irks me) making it more of an obligation to get my badge. I understand the point of 'if you don't want to do it, don't do it', but the badge is, fortunately, more of a draw.
I played GC and got those badges (which, haha, I have to revisit to get the new badgelets); I've given up completely on Word Marathon; I've grown to loathe that Crystal Ball. I am waaaay more in favour of rewards that don't come from playing and playing and playing every. single. day. for years. It's a feat to say you've done it, sure, but surely we can think of more options than simply sticking with a game for a long time to signify 'trivia prowess'.