Unfortunately you are way off with pretty much everything you’ve said.
Salah certainly didn’t tear it up at Fiorentina. 6 goals in 10 appearances.
His last season at Roma was his best of his career to that point with 15 goals.
After signing for Liverpool, he scored 32 goals and 10 assists in his first season. His best ever career stats by some distance doubling his return of his best season previous to that. Every year after that he has performed better than he ever did before his Liverpool career. Like I said Salah wasn’t even a guaranteed starter when Klopp signed him. Salah went to world class level under Klopp and became the best player in the premier league for an extended period of time under Klopp’s coaching.
There are many other examples of players excelling massively due to Klopp. Mane, Firmino, wijnaldum, henderson, Fabinho just never get to the level they did under any other manager.