Do you think it looks as if Jokovic has come to more or less the end of his successes?
That would he a bit harsh given he won the Australian Open as his 19th Slam title only a couple of months ago, is ranked No1 , and has recently taken the record of most weeks at No1 for men.
At his best, he is still the best player on the tour, it maybe though that he is less often at his best but it may just be that in this odd time his motivation is less consistent.
Karatsev though is the tennis story of the year so far. Ranked 115 at the start of the year, now ranked 27, and in terms of year to date points 5th.