Number of games hasn’t really changed. In domestic football in England there used to be 22 teams in the top flight right up to the very earliest years of the Premier League. Granted there are more games in Europe these days but most top players for the last half a century would play 50 club matches a season. I think the bigger change is in the required level of fitness and professional and the understanding that sports science has brought about that if you want players with that edge then you have to be able to give them sufficient recovery time.