Sanchez simply doesnt fit in the squad tactically and mentally. He might be good if he joiend Liverpool or any other club which press high.
However, when you defend with low blocks i think that he lacks of positioning and man-marking.
Also, I disagree that Klopp does only sucessfull transfers. If you see the players he purchased, you clearly see that "low cost transfers" that he did were not successful at all! Only high-bid transfers did well.
Klopp doesn’t really “do” the transfers, they have a recruitment committee process that involves an analytics dept, scouting dept etc, with manager and DOF all part of process. But since Klopp arrived it's not just big money transfers that have been a success:
Joe Gomez - 5m Euro
Matip - Free
Wijnaldum - 27m
Robertson 9m
Thiago 22m
Tsimakas 13m
They've also paid the same sort of money (circa 30-40m GBP) we've paid for the likes of Sanchez, Lo Celso, Ndombele, Reguilon, Bergwijn on players like Mane, Salah, Jotta, Fabinho, Firminho