Though no one seems to be complaining in "Preludes," the inhabitants of the poem are all suffering. They live in a run-down city and their living situations are impoverished. But it's their souls that are really suffering, argues the speaker. Their souls are filled with sordid images and material preoccupations, and so they don't notice each other's humanity anymore. To the speaker, that's the true definition of suffering.
The speaker is trying to tell us that our souls suffering because of the quality of our lives.
Actually, our speaker seems to be suffering more than anyone else in the poem.
"Preludes" jumps from night to morning to midday and then it makes an even bigger jump: back in time. No matter when the poem settles, the conclusion is the same: life has always been rough. You could set this poem forward or backwards 100 years, implies the speaker, and it wouldn't change much. Humanity will always face bleak times. It's just that some of them have more distractions than others.
Poetry can achieve time travel (no DeLorean required), but the human condition will always be essentially the same.
Eliot uses the different times of day to reveal what's going on in our souls.
"Preludes" takes place mostly in a city, one with a diverse economic classes. You have the people who are too poor to afford curling irons and the business people who don't have time to notice the rest of humanity. Neither class is portrayed as better than the other; the poor have souls filled with sordid images and the rich are too busy to pay attention to their own consciences. It's a lose-lose. In the end, we all face ethical struggles, and this poem suggests we are too busy (and filled with unsavory thoughts) to notice.
The different classes portrayed in the poem may have different struggles, but neither seems to come out on top. Everybody hurts.
In the end, the business of daily life leaves everyone too busy to notice their conscience. (Wake up out there, people.)