Backstory or setting detail, and the story you tell in your story, aren't the same thing, and you can't write a truly great novel or write and draw a great comic without both.
Some people put tons and tons of work into their background and setting, creating a really richly detailed world and knowing their characters down to their favourite flavour of milkshake... but they get so invested in hashing all of that out, or writing the fictional history of every continent in their Fantasy world that they either never get around to making an actual story and end up with something more like an RPG setting guide, or they tell a poorly structured story that doesn't start in an interesting place and meanders around, because they enjoy just existing in their world and around their characters so much, they don't realise it's less interesting for other people.
But then there are people on the other end of the scale, who write a rip-roaring story where stuff is going down! People are going places! Stuff is blowing up! ...But they never put any real thought into any background or characters, so everyone is a generic archetype you've seen in a million other comics or anime or light novels, every place is described or drawn with minimal detail... You know like those Isekai comics where every background is that same overused 3D model of a castle that's in every Isekai, and like.. no thought was put into the worldbuilding, so the clothes are all just that sort of... generic "Fantasy dress" you only see in webcomics, where peasants dress in sort of early medieval style clothes, but then the maids and butlers all dress like they're from Victorian England and the male royalty wear early 20th Century formal military uniforms? It's boring, uninspired, it looks like everything else and has no personality. It's basic.
The latter is easier to read, but you'll have forgotten it immediately after reading it. Specific detail is what gives a work personality, and yeah, you can't get too bogged down in it if your goal is to make something the audience can enjoy, but you shouldn't neglect it unless you truly don't mind your work being disposable. Some creators are fine with their work being just a "snack" that somebody consumes and discards, because it can make money, but others want to make stuff with a bit more staying power. If you get that perfect balance of both, that's when you get stuff that really sticks in people's minds, like Fullmetal Alchemist, or Final Fantasy VII.