I actually feel like most of the actors in Avatar haven't done much of note since then. You've got Zoe Saldana who's arguably had the most success out of the cast besides Sigourney Weaver with franchises like Guardians of the Galaxy and Star Trek. Then Michelle Rodriguez with the Fast & Furious franchise, though she hasn't done much outside of them in recent years.
But then you get to Sam Worthington, who's had a few roles in some major films since then but is far from the star that Hollywood tried to make him out to be in 2010. The only major role Stephen Lang has had since Avatar was in Don't Breathe, Giovani Ribisi has had roles here and there (most notably the villain in the Ted movies), Joel David Moore hasn't been in much either.
Actually it seems like the actresses in Avatar have been more successful than the actors since then.