I've been watching tennis since late 90's and it's not as simple as you make it out to be. The trio of Federer, Djokovic, and Nadal are easily greatest tennis players ever and will perhaps stay that way for a long time. You have no idea how difficult it is to stay as consistent as they have and not let anything get in their way. I remember watching Sampras, Agassi rivalry and thinking to myself it will never be surpassed. In that era those two did not win GS titles that consistently. Then Federer came along and I remember tennis forums in 05/06 saying that nobody will even get close to Federer. Then Nadal came. Then Djokovic came.
I also remember folks thinking Del Potro and Wawrinka will take away the reigns from the trio when they won GS titles. That didn't last long.
Point is these three have been incredibly consistent. Tsitsipas had to basically overplay to win those first two sets, while Djokovic and Nadal are so good that all they need to do is MAINTAIN THEIR CURRENT LEVEL. Sometimes you just have to bow down and admit these players are that good. Next gen is good, but they are going up against objectively the GOAT's of the sport.
No, I disagree. You are vastly underestimating the mental strength aspect in nexGen players. Seriously, Djokovic's level in sets 1-3 was simply subpar. Way below the level we're used to, and it's a level of play Tsitsipas should be comfortable playing against. I've seen Tsitsipas play oustanding Tennis, the kind he played today, for entire matches. Consecutively too. I've also seen his dip in form shown in set 3-4 in other high pressure situations, such as the grand slam semi against Medvedev. This wasn't Tsitsipas playing in his "ungodly no.1 level" dipping to his base ability. This was Tsitsipas playing at the level he's capable at dipping to the level of a world no. 50 player.
Comparatively there's no pressure for Djokovic. Sure, breaking the no. 20 grand slam is some sort of pressure I guess, but he has the confidence of winning over a dozen slams in his psyche. It's easier for him to maintain his cool. The level he showed today was beatable, and he had basically given up UNTIL Tsitsipas decided to give him a fighting chance by shanking basic groundstrokes and losing his first serve.
Notice how once the pressure of beating Djokovic and becoming the first ever Greek champion vanished Tsitsipas went back to normal? Started serving properly again? Started returning again? Started challenging Djokovic again?
It's clear at this point it's no longer a matter of physical and technical ability for nextGen. It's a mental hurdle they just can't seem to break through whenever they have a chance to beat them.
Medvedev played at a level comparable to prime Djokovic at the Australian Open. The moment he reached the finals he could no longer serve (one of the best servers in the tour), defend, or attack. And it wasn't because Djokovic was outplaying him either, Djokovic was also in poor form. Medvedev went from very little unforced errors throughout the entire tournament to playing nothing but them in the finals.
I know grand slams are an entirely different game, but it should be pointed out that nextGen has no issues beating the big 2 outside of grand slams.
It's all mental with these guys. These guys grew up idolising Djokovic/Nadal and it looks like the pressure of breaking their monopoly on the grand slams is just too much for them.
Don't get me wrong, Nadal and Djokovic are goats but they are also lucky that the only contenders after the "lost generation" just happens to be weakest generation of tennis players in decades.