On one hand I kinda feel this, but on the other I definitely feel like it's on some level a limitation of an artist struggling to deal with his own fame. You either try to recreate that lightning in a bottle and create something that kinda sorta satisfies that itch, or you try to do something new and risk alienating everybody who liked old thing in the first place.
Personally my big issue is that it doesn't look like Disenchantment is, well, a show about anything, at least not yet really. Futurama is a work comedy disguised as a sci-fi parody show. At its core it's built around the same fundamentals as any good office sitcom: Snappy character dynamics built around the irl dynamics of the sort of workplace the show is set in (in Futurama's case, the sci-fi adventure crew). Simpsons is a regular family sitcom with an unbelievably expansive extended cast and unreasonably expansive setting. Disenchantment is... uh... what?