Hubert Hurkacz and Craig Boynton are doing amazing work in tennis as is Medvedev who is shortening the gap between himself and Djokovic.
That is according to Boynton himself who had many chances to watch Medvedev closely. He observed some of his matches against Djokovic as well and asked about the admitted the Russian is getting closer albeit he is not there yet. He said:
"We are in a process of regrouping. There is the top-3, Djokovic,
Medvedev, and Rafael Nadal. Novak is on top but Medvedev is making the
differences smaller very quickly. In Rafa's case, it all mainly depends
on his health."
Looking further down the rankings Boynton said:
"Then there is the group
of 8-12 players. You can never be sure which one of them is going to
have their momentum. In order for a good result, there have to be a few
things adding: great form, no injuries, good draw, and luck. That's what happened to Hubert at Wimbledon."
Boynton thinks a new era of exciting tennis is upon us with many great tennis players that each can win. He doesn't see a few that will dominate the others:
"There is not going to be a domination like it was in the times of
the Big Three in the men's tennis. They can still win but the
competition is much closer now. It's a great time, a lot of new
faces, a lot of people hungry for success. Medvedev proved by winning
the US Open that it's not impossible to win these big titles so the
world has to be prepared for new champions."