Worst mistake of Liverpool was letting Mane go, Mo Salah won't be motivated as he usually does with Mane was around. Secretly this guys were having a competition as how they played determine who will be crowded the best player from African. Bit now there will be no competition as they're both playing in a different league, Mo Salah now automatically has the upon hand...
In regards to Liverpool big signing, they needed to do that in respond to Manchester city purchase of Haaland. Imagine a team wining the league without a proper striker but now has one. Liverpool didn't have a proper striker as well so they needed one as I feel the league will be determined by who's strikers is more hungry.
I think Liverpool didn’t have to let Mane go. But the player also did not want to stay in Liverpool anymore and Liverpool respected his decision. I also think Mohamed Salah is not going to be playing in the peak form as he was in the past. But it will be interesting to see how the new striker does.
There were clear indications of Mane leaving Liverpool before the Champions League final took place and I don't think Liverpool want to reveal that because it could affect their performance in the final. It could be that things will change from Liverpool without Mane. Well, even though they have got Darwin Nunez but he still has to adapt to the Premier League atmosphere.