CommodoreKong
Adventurer
I think qualitatively, the two movies have verrrrry different characteristics.
Detective Pikachu fits in the "Who Framed Roger Rabbit" category of movies that work despite premises that are kinda bat guano.
D&D fits in the category of well-trodden fantasy ground meets well-trodden heist movie ground.
My comparison has more to do with how well known the IPs are, budget and talk about a sequel based on box office. It's a good compasion point of what a big studio would consider successful enough to fast track a sequel (and the fact the DND movie probably wont hit that). There might be better examples but enough of the factors are close enough that I think it's a fairly good comparison.
I actually do think a live action Pokemon movie that was an adaption of maybe the first few gyms of the Pokemon game/anime probably would have done better than Detective Pikachu, properly playing off nostalgia.