The best skiers out there right now are over 30, yeah its older than the typical comp skier/park rat, but in terms of actual mental/physical performance, supposedly your early-mid 30's are supposed to be an athletes prime years. thats assuming injuries havent had a major effect, which in skiing, is pretty common.
But look at Delorme for example, IMO he is the best park skier out there right now, and he's gotta be a bit over 30 by now. Wallish, Hornbeck, some other guys im spacing, might not be old but not little kids anymore. and JP (RIP), Candide, T-Hall (despite his injuries) Pollard, Pep, etc.. some of the biggest names pushing the sport right now are well over 30.