We got spoiled with a few drafts featuring the likes of McDavid, Eichel, Matthews, Laine, etc back before 2017, who all made almost immediate impacts in the NHL. Ever since then, these were the top two picks of each draft:
-Hischier
-Patrick
-Dahlin
-Svechnikov
-Hughes
-Kakko
-Lafreniere
-Byfield
-Power
-Beniers
Out of all these top two picks over the last 5-6 years, almost none of them made an immediate impact in the NHL, and most of them have taken years to finally develop into their draft pedigree (specifically Hischier, Dahlin, Hughes). Guys like Byfield, Lafreniere, Kakko still haven't found their way. Just because there are a few from each draft that made quick impacts, it does not mean we need to make hasty conclusions about those higher up in the draft. Not too long ago, almost everyone thought Jack Hughes was a bust... now he's regarded very highly.
This doesn't apply only to Slaf, but to Wright, Cooley, Nemec... and also Power, Beniers, McTavish. Don't be surprised if they don't light up the league in their rookie seasons. Development is not a sprint.