I think Sadio Mane has achieved everything there is to achieve with Liverpool, and about his pay I'm very sure how would have gotten a better pay upgrade should he decide to renew his contract, but he seemed to be more interested in embarking on a new challenge, and the club that has been his home for many years decide to honor his decision. Even as an outsider, I hate to see him live, and I'm not sure it can get any better than it was with Liverpool.
It was more about the wage; Liverpool's offer was far below his demand; if Liverpool had met his demand, he would have signed the contract and the new challenge BS would not have existed. On a related note, he was not feeling the love because everything was about Salah. But, in reality, it was all about the money.
I think he could have paid him whatever he wanted at Liverpool. They gave 100 M€ to Darwin Nunez. If they could pay that high, they could give him the salary he wanted. Sadio Mane was playing great. Because, along with Salah, they were Liverpool's biggest weapons. I want to say that I am very surprised about this. I thought Liverpool would try very hard to keep Sadio Mane in the team.