The concerns about pro wrestler’s deteriorating health and lifespans have actually gotten much better in recent years. The WWE now has a better concussion protocol than the NFL has, and are much more wary about letting wrestlers get back into the ring early (or in some cases, at ALL) if they’ve had a serious concussion or show symptoms of what may be CTE.
Also, a large portion of what caused wrestlers to burn out their bodies so harshly in the past has more to do with how the culture used to be. It was very much like a rock and roll lifestyle, where the wrestlers would always go out drinking and doing drugs, pills, painkillers, etc. after their shows, and while naturally some of that is in response to the pain that they are in after beating themselves up all night, that culture has largely died down in recent years, especially in the WWE.
A lot of the wrestlers have seen what happens when you push yourself too hard for too long in the business, and what happens when you fall into substance abuse, and many of them have gotten smarter about diversifying their talents, getting acting jobs and endorsements and such so that they don’t have to rely on wrestling long after their body has told them it’s time to give it up.
tl;dr: Due to a combination of wrestlers getting smarter thanks to the hindsight of those who have come before, and the abject fear of lawsuits and bad PR that Vince McMahon has, I fully believe there is less risk being a pro wrestler (in WWE) these days vs. being a football player in the NFL.