I disagree, Rashford did help with the team, he played alright and he was a decent player. But 30 million deal was the reason why they do not want to get him, they assumed they could pay a bit more and get some super talented player instead.
Rashford is aging, so paying 30 million, while they are so much in debt, to an aging player, who will get worse and worse, did not looked like a good idea. Rashford also has a good contract with United, so it would be hard to match that as well. I am assuming that the best case for right now would be that we are going to end up with something much worse, and not going to have 30 million worth transfer there. Hence why Barcelona decided to not get him and look elsewhere.
What are you talking about? Rashford is only 28 years old, in modern football, that age is nothing, he still has many seasons ahead of him. And €30 million is not a huge amount for Barcelona, especially considering that just a few weeks earlier they had no problem spending around €90 million. So the real issue is that Flick simply does not see Rashford as a regular starter.
If I were Rashford, I would seriously consider changing clubs in order to get consistent playing time. It is better to join a team where you have a guaranteed place in the starting lineup than to sit on the bench and hope to get occasional minutes and maybe score a goal from time to time.