because they're not.So why do you use Big3's age as an argument to say that they're not peak?
they might rack the big titles and #1 - #3 spots in the ranking, but that only talks so much about their competition.
The older you get, the more recovery time you need.
In the case if you are past 30, or if you have friends that are past 30. Try to have a wild party and get drunk like when you were 18 or in early 20s. You'd be surprised by what awaits for you next day. Or ask your friends past 30 what happens next day as opposed to when they were "young".
Same in sport, when an athlete is young, the recovery time is way faster. Unless your opposition doesn't push you to the limits, so you don't need to recover.
When do you think Nadal was capable to run at highest speed burst?
What do you think about average speed of the sprints?
What do you think about the total distance covered while sprinting?
look into some highlights of the "baby Nadal" and see how difficult it was to hit a winner past him, cause he was getting to every ball. Is he doing this now?
Why do you think Moya talked so much about the need to change his strategy? to shorten the points?
Why do you think Novak brought first Boris and then Goran into the team?
Why Novak was so happy with winning a lot of easy points from serve? that isn't intelligent tennis, but if you don't have the speed of 10 years ago, who cares if instead of chasing every ball you rather win points by hitting aces or unreturned serves?
why do you think Fed, Novak and Rafa all went through stages when their biggest focus was to shorten the points?
let me guess, cause they don't lose speed and are still capable to outrun the entire tour day in day out, 70 matches per year.