Not a fan of the genre so take what I say with a grain of salt but I've always viewed it as the destillation of the "fish out of water" and power fantasy combined into one. Both reasonably popular tropes tied into one.

So it's already readily consumeable for the targeted demo and relatively easy to write/draw since the you don't need to worry about developing a distinct character trait/trope (he's unique/powerful) or unique narrative framing. It's not necessary bad, just easy to produce and readily consumable. It's the equivalent of the step-fantasy or fast food. Not evil or bad, just not particularly unique.

Then you eventually get amazing works (Jack In The Box's Chick n tater melt, Overlord, Eminence In The Shadow) that either push the best traits to 11 or are a direct commentary on the genre itself.