First, no matter how hard humans try to improve on natural selection, in the long run we always make things worse.
Second, we have written accounts of what the dogs were like, not eighty years ago, but over a hundred years ago, and the descriptions match what we see today.
Third, as the games get harder, after eighty-years we still, STILL have not reached a level that the dogs cannot still amaze us. With the right training, it seems the sky is the limit when it comes to their capabilities. That is a statement about the dogs that was as true eighty years ago as it is today.
Finally, we have members on this Board who have been in the game since the 1960s (40-50 years) and to a person they are of the opinion that the great dogs back then could have been great dogs today, given the same training and tools the dogs of today have.
You give us humans too much credit. It is the dogs.