The problem with making a D&D comedy movie is twofold.
One: Gamer humor is not mainstream humor. The original D&D movie had I think exactly one joke that had legs, and that was when the dwarf delivered the "...A nice dwarven woman, with some hair on her chin that ye' can hang on ta!" line, while making a vaguely hip-thrusting motion. Most of the rest - particularly the whole Snails character - just fell flat with most people.
Two: There are a few ways you can do a comedy movie. You can do something like Hot Fuzz, which is a satire of police movies, or you could do something like Tremors, where it's not exactly a pure comedy movie, but there are certainly lots of comedic elements.
Either one of those styles could work for a D&D movie, potentially - but a common feature of both those movies is that they ultimately fundamentally respected the movie itself.
Hot Fuzz worked because it was still a good buddy cop movie, and a good chunk of the humor was deliberately poking fun at those movies - but it was a good-natured sort of comedy. It was obvious the writers were actually a fan of the things they were poking fun at, they understood why it was funny, and you could laugh along with them.
Tremors was similar, but playing off monster movies.
And in both cases, the lead characters were memorable, they had clearly developed personalities, motives, and mannerisms, the dialog was rock solid, and the plots were still good plots underneath the comedy. Yet, at the same time, the comedy was integral to the movie - without the comedy, they may have "worked", but they would not have stood out.
The D&D movie wasn't that sort of comedy. The comedy was tacked on, like they were just trying to make sure they had a quota of "audience is suppose to laugh now!" moments. And the comedy didn't respect the audience, and it didn't give the feeling the authors either loved or even understood the source material. Again, with the notable exception of the bearded dwarven women joke, the jokes were just... jokes. And usually not very good ones. And too often, it felt like the underline theme of the joke was "this is all stupid".
Which, maybe it is? But I don't pay money for a movie to insult my hobby.
The character issue - which is kinda related to my whole original point that spawned this mess - is another issue. Again, to use Hot Fuzz and Tremors as examples. I remember the characters from both of the movies. I remember they had clear personalities, motivations, goals, and so on. I'm not going to say I remember all their names - I'm bad with names! But I remember them. I remember other police officers, the towns folk... the pub owners, the florist who got murdered, the reporter who got murdered, the actor, the grocery store owner. I remember how they related to each other, how they fit into the movie, and so on. Similarly, with Tremors... I remember Val and Earl, obviously, but I remember the geologist, I remember Burt and Heather, I remember Chang, I remember the punk kid, the little girl and her potter mother, I even remember characters that had very little screen time, like the doctor and his wife. Because they were all well crafted characters, and memorable in their way. And even when they didn't really have any major personality - the doctor and his wife, the two construction workers, etc - you remember them because they fit into a well-crafted web of a story. You may not remember them specifically because of anything they did, but rather because they were an element of a greater whole.
I couldn't even tell you most of the characters from the D&D movie. Thief-guy. Other thief-guy, but black. The dwarf. There was probably an elf, but I don't remember specifically. The bad guy with the dragon staff, and the bad guy with the blue lips. I don't remember a damned thing about any of them, though. Not their names - except for Snails - or their motivations or, really, their personalities. The dwarf's personality was "dwarf", Snail's personality was "obnoxious idiot", and blue-lip guy glowered. That's about it.
Which is why trying to make a D&D movie without strong established characters is going to be iffy. D&D is basically designed to be self-insertion fantasy. That's the whole point. You can't just say "The movie is about some adventurers", because adventurers without players are puppets with no strings. And the epic campaign as an hour and a half movie just won't work. You can't develop a plot or characters for a movie like that easily.