Pornography is always about the young and beautiful unless it's age-fetish specific. You shouldn't take it as real data, any more than you should believe you can be tied up like the models in it (who usually only hold the pose for as long as it takes for the camera to click).
Any Dom(me) worth the name will value you for what you can give as a sub, not how closely you resemble Barbie. Speaking for myself, I'll take a yummy-mommy over an inexperienced kid any time.