I think it's also worth noting that the guys who had the physical tools to be superior athletes might not have even gone into baseball back in the day.
The way sports are marekted, with all the youth programs, college programs, and the knowledge that atheltes are paid handsomely and parents pushing kids talented into said programs nowadays there's a far greater chance of superior atheltes being lined up with going into sports.
You just look at the average athlete today, the average athlete back then look like the guy on my softball team loading up on beer and wings every night. Oh wait, that's me.