Chelsea is actually very good at recruiting star players, Chelsea's only fault is in the coaches and club management who like to change coaches. not a useless player, but a Chelsea coach who can't maximize the potential of players. It's like what you mentioned Aubameyang and Kai havertz who said they were useless for Chelsea. Look at the goals that have resulted in titles in the past... See also Mohammed Salah and KDB being thrown out of Chelsea, what will become of KDB now at Man city?
If you say it like that, it means that the one who deserves more blame is the club management, not the coach. Because every coach must have his own way of training a team so that the time needed is also different for each coach and from what you have said, the peak of the mistake was the management of the Chelsea club itself, which was inconsistent in retaining existing coaches.
Pochettino includes the courage to train Chelsea, he is not worried about being fired via telephone like Tuchel who has presented the UCL. can he last long?
It's a new coach again for Chelsea and in general no one knows how long he can stay at Chelsea, because he will only work next season as a coach at Chelsea so every result and assessment will be seen in next season. Although Chelsea fans hope that Chelsea can make a better performance again next season.