No it didn't. It regressed. One obvious area is pocket defense. Boxers today and since the 70s use their legs more than ever. It makes for great track meets but not fights. Standing in the pocket and slipping has been a lost art. Thats why for example when a James Toney comes along they say he was a throwback in the skill department. Many modern fans believe you have to be moving around/retreating to outbox an opponent.