Kovacic and Kante were ran into the ground by Tuchel, which has led to them sustaining chronic issues. Fofana and James were a bit unlucky with knee injuries.
I think in terms of tempo, or playing at a high intensity, this has been an issue since Sarri’s reign and he was the first to notoriously question the players mentality publicly. They pick and choose when to play at a high level whereas the players at rival clubs seem to have it drilled in them every match week.
There is a deep rooted issue within the club that is allowing it.