It may be exceedingly subjective but to me the days of long poems are over. Unless you are an academic obliged to teach or study lengthy pieces, one tends to set aside lugubrious and tendentious pieces. You peruse a line or two to see if it would be worthwhile to proceed, and a quick judgement decides things for you. After the Imagist lore, poetry attracts with an image or two that intrigue and compel your imagination. That’s now poetry for me.
Only TS Eliot looks like an exception. But what is his art but a string of fascinating lines and passages strung together. You may read him in pieces if you like.