After many years of watching tennis, what I have noticed is that players look like they are on a certain course and then it can stop very quickly
In 2003, I didn't think Henin's last GS title would be in 2007
In 2001, it seemed unthinkable that Venus wouldn't get the career slam
In 1997, Hingis won her first grand slam title at 16 years old. Absolutely nobody would have expected that her last GS singles title would be in 1999 or that she would never win RG
At the moment, you look at Swiatek in particular and think she's so young still, she looks so fit and determined, how can she possibly not get there? But it happens again and again unless you get a true all time champion like Serena or Navratilova or Evert.