I agree with that. The wheels fell off after the season, where him, Martial and Greenwood really shined. Lot of it is probably connected to other teams still underestimating us therefor let us play on the counter. Rashford in that season tried to create and facilitate for other, it was great to see. The year after, he fell into a hole, especially his decision making went completely out of the window, all the strikers wanted to be the mainman, wanted others to create for them. Rashford still had a good games here and there, but often, iirc, this was connected with a bad decision like running into 3 people working somehow. It still were bad decisions though.
Lets hope, the current trainer team is able to teach him a thing or two, Rashford has lots of the tools necessary to succeed in the PL, he is fast, he can be a good dribbler and his finishing is good. Now somebody has to get his head in shape, to bring him into positions, where his strength can shine. Same applies for Bruno too btw.
Do I think, Rashford can make it work? I am a bit worried, but Pep made something out of Sterling, so that gives me hope. Rashford might not be the awesome player we all hoped he would become but he still can be a vital player.