On the other hand, the talent pool has grown immensely over the decades.
Basketball in the 50’s was nothing, by modern standards. The NBA in 1956 had 8 teams, including Rochester, Fort Wayne, and Syracuse. The games weren’t nationally televised, salaries were low and many of the players had side jobs to help pay the bills. In 1962, Elgin Baylor was in the Army reserves in the week and only played games on the weekend. The US population was half of what it is now, people were shorter on average and there were very few foreign players.
Despite all that, Kareem Abdul Jabbar grew up in that era and became a skilled, athletic 7’2 player.
With a larger population, an international fanbase and huge financial incentives to identify and train tall kids, the odds of producing another freak like that is way higher than it used to be. There aren’t many healthy 7’6 humans out there, but if they exist, someone will find them and groom them for the NBA.