•Why it earns a slot
Why it earns a slot: Dreiser refuses to punish Carrie or reward Hurstwood; the ending hands her everything she wanted and still leaves her rocking alone by the window, a verdict on ambition itself.
A country girl trades poverty for a rich man's money, a rich man's money for stardom, and stardom for an empty rocking chair by the window.
This distillation is written from the freely available original, which is always the better read when you have the time: Project Gutenberg.