I think Tuchel has been a little unlucky (Vs Someone like Liverpool) with the way the fixtures have fallen and the injuries they have sustained.
In the past week/ 10 days their key players have played nearly an extra game vs Liverpools because of the fact that Liverpool drew Benfica and had the luxury (Through no fault of their own because they can only beat what's put in front of them) to rest players in the second leg before their semi vs City.
Chelsea did 120 at the Bernabeu , then the semi with Palace and a tough game vs Arsenal (Who are suffering their own injury problems but have far fresher legs).
Last 3 games;
Mount 290 minutes vs 200 Thiago
Alonso 290 minutes vs 180 Robertson
James 300 minutes vs 180 TAA
Werner 260 minutes vs 200 Mane
Etc etc
You add that to injuries to key players (Kovacic/ Chilwell) with sub par replacements , the disaster which is the Lukaku signing and the uncertainty around the club (Ownership, contracts and attendence down) and it's no surprise they don't have the same spring in their step as Liverpool.
I think it's a credit to Tuchel that he avoids bringing any of this up because I've heard some fans blame him for the result last night but I'm not sure what else he was supposed to do with the hand dealt to him.