33 in combat sports is old, especially for a fighter with the miles Fedor had on him.
He’d been in MMA for over a decade by the time he fought Werdum, and had been doing Sambo for 20 years.
I know for Millennials and their bastard offspring Zoomer trash who’ve never done anything even remotely close to sports or competition in general, this will be a foreign concept, but athletes have an incredibly short shelf life.
Running backs in the NFL have maybe 5 years, at best, before their bodies start breaking down. NBA players about 10.
Now imagine getting punched in the face for a living for 10 years straight (because they’re eating shots in practice every day too, regardless of protective headgear), and you might start to get a clue. Or not.