I cannot agree, Brad. Zverev, Tsitsipas, Thiem and Medvedev are all great players, and would very likely be owners of several Grand Slams each... in any other era. Same for Murray and others, years ago.
But they are unlucky to be coetaneous of the three greatest players ever. And yes, I was a big fan of Bjorg, McEnroe, Lendl... not so much of Sampras. However, there is a huge difference with the big three. Federer would own 30+ Grand Slams if Nadal or Djokovic would have not been there. And same the other way around.