Even Murray, who literally has a metal hip that severely impacts his movement and ability to rotate into shots, is able to push him to the absolute limit. It is stupefying to suggest that Stefanos is ever going to be the undisputed best player in the world in really any scenario, to me.
What I think is more likely, though, is that using a time machine, Tsitsipas may initially beat some of the guys from 03 who hadn't seen his style before, but as with anything, they would adapt, figure out his weaknesses, use some of his techniques, and eventually usurp him and beat him regularly.
I generally think that sports, and athletics in general, are incredibly reactive pursuits. And reactivity is really how the game evolves. Someone starts doing something new, the opponents have to catch up, the level raises. And specifically in tennis, technology (both strings, racquets, surfaces, shoes, and general nutrition/training) causes new variables in the game forcing players to react. So this is why you might say on an absolute level 2023's top players are the best ever (I disagree, I don't think they're much better than 15 years ago - maybe 25 to 30 years ago, but that is mainly technology)
To make this short. You can draw such an obvious through-line for each level of player throughout history that I think much of this is just about the circumstances players have imposed on them. I don't truly believe any top players are that much better than others, just subject to different circumstances. Tilden beat Budge, who beat Gonzales, who beat Laver, who beat Borg, who beat Lendl, who beat Sampras and Agassi, who beat Federer, who beat Djokovic, who is now beating Alcaraz. Albert Pujols just hit 30 home runs at nearly age 45. LeBron James who played against Gary Payton and Karl ****ing Malone is still the best player on the floor in certain playoff games vs. Jokic, Tatum, Anthony Edwards, etc.
I think that 2023 players are allowed to do things that were not possible 20 years ago. For example Lleyton Hewitt played in 03 but he didn't slide on HCs and also wasn't using poly back then. However, even after suffering serious hip injuries, Hewitt was still out moving top players in the early 2010s, Federer among them. So it suggests to me that these players are not better movers, they specifically train to slide and play on surfaces and with shoes deliberately engineered for that exact purpose. And we saw old guys like Hewitt in 2013 upset prime “evolved” Del Potro in Flushing using this new movement principle even if it wasn’t a staple of his 00-05 movement.
