I've never been a fan of Chekhov's gun. Interactions and details that aren't directly connected to the main plot do a good job at giving the world texture and making it feel alive. Fiction that does away with too many unrelated details (and I'd argue a lot of fiction does this) often feels artificial and empty to me.
There's a line, and it's different for different people. For example, for me Neal Stephenson plays right along that line pretty heavily, but does it well. He fills his stories with so many digressions and tangents about what the ramifications of the things he's envisioned are, that you're never quire sure whether he's rambling, of if this tangent it going to be one of the few that's integral to understanding the weird resolution he has planned at the end, and not just a fun bit of world building.
