Doing impact sports (football!) professionally or fighting professionally and staying healthy is just not possible without neutering the sports. Maybe this should be made even clearer.
https://en.wikipedia.org/wiki/Chronic_traumatic_encephalopat...
You can imagine her reaction when the NFL played stupid with "we had no idea the players needed so long to recover" 40 years later.
I think helmets were, to a large degree, merely there so that the fans could pretend players weren't getting concussions as often as they really were. Boxing fans (and non-fans) are aware that getting hit in the head a lot is bad, but there aren't enough boxing fans in the US to fill a single NFL stadium, much less 16 a week.
Not necessarily: The increased and stacking vulnerability to brain damage after concussions might not go away ever. I don't think this has been researched.
There are some permanent cumulative effects of concussions, though it's pretty well-accepted that repeated concussions in close succession (without sufficient time for recovery) is worse than concussions that are spaced out. Second impacts are much more likely to have serious consequences, including death, than initial impacts of similar magnitude[0].
You'll never get "definitive proof" of this because a double-blind study would be extremely unethical (let alone impractical), but there's enough understanding of the underlying science to make this conclusion relatively safely.
In short: repeated head injury is bad regardless of how much time is allocated to recovery in between and has some permanent cumulative effects, but repeated head injury in short succession (for some definition of "short") is markedly worse.
There used to be. Boxing used to be huge. I've seen the theory floated that the reason boxing died as a spectator sport was precisely that all the fans got to watch their heroes lose their minds.
Do you have any proof for this at all? The most anticipated boxing matches usually get over a million pay-per-view buys, not including the tickets sold for the actual arenas.
[edit]
Yes, there are literally more than 80,250 (MetLife stadium's capacity) fans of boxing in the US. However e.g. the Kingdom Arena (location of Fury v. Ngannaou) seats about 30,000. If there were a 17 week boxing match season in the US, it clearly would be a much smaller draw than gridiron football, and that doesn't even include the college game, which has 8 stadiums that seat over 100k (and 6 more that are larger than MetLife).
Well the first I heard even doctors making a big deal about them was the mid 2000s CTE research. And even that research was strongly linked with just one lab at BU iirc. It sounds like you're comparing the NFL to big tobacco. As much as I detest NFL commissioners/management, I don't think that comparison tracks with the science.
American Football, like Australian Rugby is a much more violent sport.
Here's some hard data.