Imo Mc Allister is another type of midfielder. He's more of a ball carrier imo. And surely he looked fantastic in the World Cup but I don't think I could say the same in the PL.
Actually imo it's very hard to replace Bruno atm. His insane work rate, his passing, his creativity, his drive, his goals, his assists. Very hard to find an attacking player with this kind of productivity while still contribute very well in defensive duties and love to do the dirty job. Griezmann might do the job for a couple years but I don't think he'd be as good as Bruno.
Tbh I simply can't stretch how important he is for us atm. He's surely frustrating to watch sometime but his desire and always giving his all alone makes me really really love this guy.