The worry is his technical limitations. Benzema, Ibrahimovic, Kane etc didn't become technically good in their mid twenties. They had that aspect. Some had to become stronger something you can work on in the gym, some had to gain composure in front of goal which sometimes comes with experience, some had to take on more responsibility which can come once they start to see themselves as a more senior member of the squad. Technique hardly goes from were Hojlund is to were a Lewandoski is for example which should be the standard at Man utd. He looks to me as the sort of player who would play as the main man in a b-level club but not in a EPL winning, champions league winning side.
He has time to prove me wrong though, I actually admire his work rate.