With nutrition and better strength training, the players are getting bigger and faster. The impacts on the field are more intense. Yet the real problem is that the protective equipment has not caught up to the athletes. I think better impact resistant padding will overcome the negatives. I heard one sports talking head say that in 20 years the football uniforms will be like Batman's get-up, he then laughed but the other host then chimed in to say he could, seriously, see that. Ags in Kevlar uniforms would be something.
Football will be around in 20 years, keep building those priority points.