You say I exaggerate but don't say how. You want to wait for De Ligt for what exactly? He is 23, he's gonna be improving regardless of environment. In a few years he's likely the best CB in Europe, but people will come here and claim we were ruining him while Bayern made him great. Dybala is Dybala at this point, I don't think he will level up. What do you think of Kulu and Bentancur?
Not necessarily. Coaching and environment absolutely matters especially during formative years. There is a reason some clubs are better for young players' progress than others. Game time, role models, tactical training, fitness training and conditioning methods, winning mentality...variety of factors influence whether a player will fulfill their maximum potential or stagnate. Salah wouldnt have gotten this good if he had stayed in the Egyptian league. De Ligt's skills when he is ~28 years old, would have definitely been influenced by whether he honed his craft here or at Bayern or in the Egyptian League. Personally I am not sold on him becoming best CB in Europe no matter where he goes. He can be one of the solid reliable ones in one of the top teams but "Best" strikes me as too high for him.
Bentacur is a useful average/above average midfielder not the utter shit that we witnessed. Not gonna set the world alight either. I dont think he'd be a gauranteed starter in any team thats challenging for EPL title but a regular for top 4 sure.
Kulu has serious potential he can be a top winger and can start at a bigger club if he fulfills his potential.