I think of really long books like really long songs. Your average book or song is 300 pages or 3 minutes. Some bulk it out to 500 pages or 5 minutes. Occasionally, you get a book of 1000+ pages or a song of 10 minutes or more.
There are two types: those that deserve—that demand—to be that long, and those that need better editors.
The longest book I’ve ever reread is probably Gone with the Wind at 418,000 words (and three total reads). What’s yours?