"As public awareness of CTE research has grown, there has been a decline in participation in youth and high school tackle football and a rise in participation in flag football."

...Thirty years ago, through the winter of 1994-95, the NFL began its slow transformation into the very different game that is played today. Reacting to serious concussions suffered by several of the league’s star players, including Dallas Cowboys quarterback Troy Aikman, then-league commissioner Paul Tagliabue took a big, if seemingly begrudging, step. Despite describing concussions as merely “an occupational risk,” he created a brain injury committee. 

Since then, dozens of new rules, new equipment, and stiffer penalties have been put in place, all with the intention of trying to reduce the number of concussions players sustain...

...In recent years, much of the public pressure for change has built because of research out of the CTE Center, under the direction of Ann McKee, a William Fairfield Warren Distinguished Professor. McKee has previously said she was a “lifelong football fan,” but she now views the game as dangerous and says that “football damages brains, and young brains especially.”..

https://www.bu.edu/articles/2024/research-on-cte-changed-the-nfl/