system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is it that modern professional athletes are/seem so much more talented than original teams in the past?

I understand that equipment gets better in relation to better technology but why does it seem that, for example, a modern NHL player would just absolutely demolish a player from, say, 1975. Are there other underlying reasons why it seems that modern teams are more talented than their predecessors? 

BASICALLY, why is it that the overall skill level seems so much higher in today's professional sports?
gpt
Money, technology, retained knowledge, cooperation between sports and other fields.

A professional athlete from 1975 probably started playing when they were young, then started taking it seriously when they got higher up in rank. At the same time, they were probably working to support themselves. A modern pro-athlete will have spent a lot more time training by the time they are 18, then they are compensated a lot to maintain an intense training schedule.

When the athletes are training, they now have cheap stopwatches, flat springy surfaces to train on, isolation machines to grow specific muscles, ect, ect. This is much better than what was available in the past. 

The coaches and trainers and even parents of athletes have the benifit of looking back at past athletes to see what training methods worked and which didn't. Therefor, the modern athlete will be given better instruction during their training with less chance of injury. 

Fields like medicine, engineering and nutrition have all contributed to the pool of knowledge that the athletes, coaches and trainers can draw from. Some things are simple like the lesson of tackling lower to give you more leverage. Other things are more complicated like supplementation in the diet of creatine, protein, ect.