Just because Federer made them look bad doesn’t mean that Tsitsipas would have done it.
I think part of the issue is he is not shooting too much. In 12 games he shot 15 or more shots in just 5/12 cases
It creates a variety in his game and keep the defenses honest and guessing.
And he is just 30, could easily score another 30 goals if he plays till 35
At least he won enough money to show for his dedication, not to mention he was out of top 100 till what - 27,28?. 5.5mln from prize money, at least 1.5-2mln should be net for him.
To be happy and enjoy here time on Tour. The rest will come