I love Doom, but he doesn't translate easily. The problem is he's goofy. And terrifying. You've got to somehow build a character who can simultaneously believably take the place of God and hold the entire universe together out of sheer strength of will, and say lines that are the cheesiest goddamned things ever, speaking in the 3rd person all the time. You somehow have to have someone deliver lines like "Now you all shall feel the wrath of DOOM!" or "Doom shall aid you but only because Doom wills it." and have that actually be scary and powerful, rather than provoke a laugh.
Otherwise, you may as well have Squirrel Girl swarm him with squirrels and sit on him till the cops show up, because he's never going to be less silly than that.
I'm sure it can be done. I just don't see an easy path there; you need perfect casting. I do agree that a better intro for Doom would be a Doom-centered film entirely, but they're gonna have to be careful that Doom still presents as an anti-villain, not an anti-hero, the inverse of Loki basically. And since he's a brutal totalitarian, it has to be clear his ideological views are brutal and harmful, otherwise the whole thing'll come off as pro-totalitarianism. All those are challenges to doing this "right".