I feel I have a very different view of the game than quite a few people here.
I look at Rashford as a magical story. The debut days when he stepped up with insane goals out of nowhere when LVG needed them. How he scored on almost every debut he had as a teenager, and how he celebrated them as a local lad who'd come through the academy and grown up loving the club. How he idolized Rooney and ended up taking over the goalscoring burden from his idol while keeping his head down and going to school. How he handled the inevitable drop off under Mourinho and turned up under Ole again. His insane big game record when we had that fairytale run under Ole, that PSG game in particular. How he single handedly got a government to reverse its decision to let children go hungry, and how he did it while facing racism and unfair criticism from quite a large part of the country including his own club's fans. His ability to always keep himself available, even though it came at the cost of his injuries. The sheer joy of some of his goals. Knuckle ball free kicks, elastico skills before selling defenders (White, Demechellis, Dunk, T. Silva off the top of my head) and slotting home, being a terror in counter attacks with pace, control and finishing, his intelligence in link up play.
I felt incredibly proud when he scored that 100th goal. He may not end up in the list of greatest left wingers or center forwards, but he's definitely had a very special career both on and off the pitch already, with many years and a peak still left in the tank.
I do not understand how we can reduce this story to a mere binary decision of sell or not sell, based solely on the arguable impression that he may not be the best player we could have there. Money may buy you a better player, but it can't guarantee better results. United fans who jeer at "mercenary" players and have witnessed almost a billion pounds wasted on big name players who never turned up should know.
Even keeping the priceless nature of his time at United aside, the sell argument seems incredibly naive to me from a logistical perspective.
Is there a clear cut replacement who is guaranteed to be demonstably better AND wants to come play for us? Sancho had better numbers and he's struggling to break through. Before him, Martial kept getting injured and didn't run enough under Mourinho, and we know what happened with Alexis Sanchez. Bar the likes of Neymar, Mbappe or Vinicius Jr, who is demonstrably better?
But let's assume there is. Let us assume there exists such a player who'll want to come to United and replace Rashford in the starting XI. Maybe Sane, Dembele or Son. In that case, do we not need a backup or a rotation option? Would it not be stupid to let go of a young, homegrown, rapid, hard working, versatile big game player who has shown the professionalism to sit on the bench and fight for his place? In a market where options are far and few and all expensive? It's not like we need to make money from sales.
This thread is madness. It's full of FIFA rating-based reasoning where people apparently know the price of everything and the value of nothing.