I think you're being a tad harsh. Football was different then for a number of reasons. Not only has physicality improved as a result of diet, training, facilities, sports science etc, but also in those days - balls were way heavier, boots were heavier, pitches were "heavier" (muddy, scuffed). The result of all this combined was a game at a slower pace, teams more stretched/less compact in their shape.
Obviously if a footballer from 60 years ago was teleported to today and had to play immediately they would struggle. Give them a few months of conditioning and practise with modern balls, boots and tactics, and the best then would obviously make it today. The skill, intelligence, determination and creativity, courage that made them the best of their era, would be the same core attributes needed to become a footballer today. Likewise, take a modern player, time travel them back 60 years to play on old pitches, with old balls, and a few months without the modern support aides, and they'd struggle at first but in time would adapt.
I've never understood this argument when analysing players from previous generations. All of this should be a given, it shouldn't even need to be said. What matters is the skill relative to their peers. Perhaps a chess comparison may make sense to people. Paul Morphy is considered one of the greatest players to have ever lived, and destroyed his peers. Today, if he played the same moves that he played then against an average competitive player he would likely lose - the modern players have over a century of games and positions that have been analysed, and strategies have been refined. The modern player can learn from this century plus of knowledge relatively quickly. Morphy on the otherhand had virtually zero pre-existing knowledge and analysis to use as a starting point. On his own, he came up with strategies and concepts which not only separated him from his peers, but which are still prevalent in chess to this day. Was he better than today's average competitor? Hell yes! Was he better than more recent world champions like Fischer, Kasparov or Carlsen? Nobody can possibly say!