Looking at those ages ago now is completely different thanks to training techniques like crossfit. While not the fastest or most impressive looking, Tommy Dreamer is 50 and still going strong (and finally morphed into the modern day Terry Funk).
Guys in their 40s wrestle like they're in their 20s still (or at least 30s). AJ Styles. Eric Young. Rey Mysterio. Ron "R-Truth" Killings. Bobby Lashley (this is probably why WWE won't give him the title, the bastards). Shelton Benjamin. Bully Ray. Christopher Daniels. They are able to kill it in the ring athleticly still. It's a huge difference to wrestlers of the same age 2 decades ago.
Hell, last indie show I went to I saw a fakking Pitbull wrestle. They stopped being relevant midway through ECW but he looked and moved pretty damn well in the ring at his age. He wrestled what many of us think is a grandpa. Who moved decently as well.
Also, Terry Funk was an anomaly. Same with Ric Flair. They looked very different and moved very different but could go when needed. It was very impressive.
I remember years ago feeling bad for older wrestlers like Chief Jay Strongbow who continued to wrestle against much younger opponents. They were no match physically for the agile, well trained youngsters they went up against. Some of them were monsters like Superstar Billy Graham, Ken Patera and the Hulk or quick as lightning like Bob Backlund and Mil Mascaras.
Some of the guys still going today is nuts. Ricky Morton and Robert Gibson, The Rock and Roll Express at ages 61 and 62 were recently the NWA World Tag Team Champions. Mil Mascaras is 77 and his brother Dos Caras is 68 and they still compete occasionally in Mexico and Japan.
Sabu is 55 now and still wrestles and Jerry Lawler who is 70 still wrestles on the independent circuit, and this is after having a stroke a few years back.
Some of the guys need the money and this is all they know, I get that. But some I guess just do it because they can't get it out of their systems.
On the WCW topic, Flair was in great shape for being 51 when he last won the WCW title.