Their is some measurable chance the NFL and football disappear w/in 30 years. Sooner or later a college / high school will lose a lawsuit for a player w/CTE, and schools will have no choice but to stop participation. Once that happens, talent level and interest in the sport will die off. Kinda silly cities are in such a rush to continue building new stadiums.
The unspoken elephant whenever these studies come up is skiing and snowboarding. Lots more participants, and I bet the concussion rate is similarly high over X number of visits. Damn well better not make me wear helmet though, my worst injuries came when I had one on (overconfidence syndrome)