I don't think RR implied that the players have given up with that statement. He was being descriptive rather than critical, and he tried to get across the message that we need to rethink our whole recruiting process.
We have too many players who pull away from 50/50s the moment they realize that the opposition player stands a (slightly) better chance of getting to the ball first. In fact, except for Bruno, our entire frontline consists of players like that. You can't always rely on rapid pace or finding the perfect pass and finish to beat defences. You have to make the defenders work for their meal, and we usually don't. Another thing, is the cursed second balls. One of the main qualities that allow both City and Liverpool to pin down teams and retain their attacking momentum is winning the second balls. This is actually where i disagree with Rangnick. He said this can be taught. It's true that it can improve with better spacing and better positioning, but i doubt you can teach things like awareness, anticipation and good reading of the game. I still remember when Klopp went to Liverpool and SAF's comments on Henderson (and Rodgers' response to them) were still fresh, the German was asked about it. His answer was that the analytics team indicated that no one in the PL wins more second balls than Henderson, and that this is a quality he needs in the side. Needless to say that both Pep and Klopp value it greatly. On the other hand, there's a reason why we, even under Solskjaer, resorted to McFred as our more well-functioning partnership in the middle of the park. Not because they are good with the ball (everybody can see that they are hopeless), but because they are the only players in the side who don't hesitate to throw their bodies in the fire and, most importantly, they are the only ones who actually react in the first crucial seconds after we lose the ball.
We need to start playing Moneyball in the market. We should identify what we lack as a team and then use the stats to tell us which players are the best fit for the team. It's a disgrace that it took us up till 2021 to hire a sports analyst. People need to realize that City and Liverpool not only have the best in class to manage them, they also use whatever tools available to help them focus on the first team preparations and improvement instead of running the whole club on their own. I believe that's what RR is talking about, but i doubt they'll listen to him.