What makes Cane a classic?

Didn't finish the 2nd section of Jean Toomer's "Cane," but I'd have to say that this section - set in the U-Street corridor of DC, then (1920s) and now a black neighborhood, though getting more upscale by the minute, is not what made or makes Cane a classic. Compared with the first section with its surprising and unique blend of poetry, fiction, short character sketches in rural southern Georgie, the DC section feels weakened - we get sketches of nightclub dancers and more descriptions of femmes fatales, mysterious beauties who drive men to irrational lengths and then abandon them - and grow older and less attractive - a theme of Toomer's repeated again and again, with variations. Reading Cane, I do appreciate his willingness to and ability to use a whole range of literary devices to give a portrait of a community, but he doesn't actually paint a portrait, he just sketches the outlines. He has terrific material with which to work, but he doesn't develop this material in an traditional way. I find myself waiting for, hoping for some plot - which would entail bring the characters and places together, following one character through at least several of the scenes, developing a thread that connects the first two (and the third) section of Cane into a unified work. But I guess what makes Cane famous is that these threads willfully do not exist - it's an open, breathing work, no far removed from the author's sketchbook or notebook. In that way, it broadened the scope of literary fiction, edging it as close as it could get to Symbolist poetry and looking forward to the impulsive and explosive writing of the Beats - but it does seem to be hinting at, promising, something that it can't quite deliver.