I'm from Chicago, so I might hold too much weight on the importance of this album -- but it's a big part of Chicago music history. That mixtape caused Drill to spread like wildfire throughout the metro area and Keef completely dominated the music scene for a solid two years. Drill was the most organic movement in hip hop in a long ass time.
It was fun while it lasted. It's still big in the streets, but Chance stole a lot of the local spotlight. The narrative around Drill and the violence in Chicago didn't really help it in the long run either. Plus Keef couldn't keep it together. And all of the deaths. I thought Herbo and Bibby were the most talented of the crop, but they weren't going to breakthrough. They'll have their little run though, which isn't bad. They took their talent and got out of their situations, who can hate on that?
Back from the Dead is definitely a classic imo. It's the defining Drill project.