In genre fiction, plot is usually most important, closely followed by setting, with characterization less important (stock characters are acceptable), and prose merely functional. Some genres swap the importance of plot and setting, e.g. fantasy follows the influence of Tolkien and highly values setting.

In literary fiction, the order of importance is reversed. Prose quality is paramount, closely followed by characterization, with setting existing only to serve the characters, and plot hardly relevant at all.

This on the surface makes for boring works, but prose quality actually has the highest skill ceiling of all, both for writers and readers. "Quality" in this sense means "skillfully using words in the manner of literary fiction", which is difficult to detect if you don't read it, but it's a real thing. As appealing as it to assume it's all a big scam, the best literary fiction writers really are better, and the readers can tell, just like you can detect AI slop at the other end of the scale. I imagine if you put enough effort in it's even possible to enjoy reading Finnegans Wake (the final boss of literary fiction).

Plot/setting/character have real life as a reference, making them easier to master.