MegaTronBomb!
Power is in my hair nikka
The best athletes have ALWAYS played skill positions. Coaches weren't idiots who pigeonholed all of their talent on the offensive side. There's no way you can prove what you're saying. You had to have and still do need a certain skill set to play offense. They weren't going to stick some fast, shifty dude at RB if he had no vision or fumbled all of the time. They weren't gonna stick some fast guy at WR even if he couldn't catch or run routes. Deion Sanders is one of the greatest athletes of all time. Night Train was one of the best physical specimens to play and that was in the 50s. I can go on and on and that's just cornerbacks.
You keep speaking about carries but I just looked and what you're saying isn't true. Maybe it is once you go further down the list running backs but the league leaders in attempts (and not just THE league leader) are still in the same range. Hell the Texans almost had 2 1,000 yard rushers a couple years ago. You also aren't taking into account the faster pace of the game which allows for more plays. I wouldn't be surprised if the length of games have increased due to more plays being squeezed in.
Carries are going down. less and less players are getting 300+ carries like they did 5-7 years ago... not even counting the anomalies like Larry Johnson getting 400+ carries, the last two season have had the fewest players carry 300+ times in the last 10 years.