Pro football goes through phases and right now the quarterback who can run and throw is highly valued. Lamar Jackson is revolutionary and other teams are trying to duplicate Jackson's successful run. When Jackson was originally picked, it was expected that he would be some sort of hybrid. Instead, he became one of the finest players in the game.
Nearly twenty years ago, the Patriots made a virtually unnoticed trade for a white, pint-sized spare receiver and kick returner named Wes Welker. Welker revolutionized the position of slot receiver. Other teams also tried to make slot receivers stars but none succeeded like Welker. Today, the slot receiver is pretty much phased out of football. Perhaps that's because there are no Tom Bradys around who have the discipline to make an eight yard hitch throw.
Football has changed radically in the fifty-five years I've followed it. The first Super Bowl I can remember is Super Bowl 3, Joe Namath's claim to fame. The New York Jets and the Baltimore Colts were three-quarters white. Today's NFL is three-quarters black. I remember the position of nickel back was adopted by George Allen when he'd replace the middle linebacker with a defensive back on third downs. Nowadays, teams often have seven defensive backs in the game. Allen was one of the first coaches who put great value in special teams. Today, the kickoff has been de-emphasized because of the fear of injuries. Fullbacks used to be vital to an offense. Think of Jim Brown and Jim Taylor. Now the fullback position is almost obsolete and most teams do not have a fullback on their roster. Teams that have fullbacks rarely have them run the ball.