I guess the only thing to say is you'll come around to the opinion I'm sure as he continues his form and eventually changes your mind. He's genuinely just a very good right back now. Yes he's a top 5 RB based on this season's form. Mind you there isn't tons of quality RB's in the world, but the ones you mentioned, nah no way. He wouldn't bench Cancelo for the national team if he was some mediocre player ffs. Mazraoui, come on. He's started 6 games in the Bundesliga ffs. Bayern chop and change right backs every game and move their best midfielder to RB occasionally, but he's ahead of Dalot? Come on. And he is now set as our long term right back precisely because he's shown an excellent level.
You do realize that Diogo Dalot is only 23 right? And already has benched one of the best fullbacks of the past 5 years for his national team and is the current and long term undisputed starter for United? It's shocking to me that some can't see that he's become a very good player and that the manager loves him.