I don't think the dark fantasy theme is a dealbreaker. Personally, I enjoyed works like Heavenly Delusion, and find the story (and story-telling) of The Promised Neverland fantastic, up there with the greats.

It's just that for some anime, the dialogue and character-acting felt so off the mark.

Ultimately, entertainment / enjoyment is subjective. It's nice to see that you stayed true to yourself instead of bending to peer pressure.