[ghostoftiber]

I am also a hobby beekeeper. My sample size is "2" - I always have two hives. I also had both hives die out last year after 3 years of not needing really any help at all. The one colony didn't really have any signs of mites to speak of. There were just a bunch of dead bees in the bottom of the box. The other colony absconded or was overrun. They had a decent-ish amount of stores they left out, but no bees whatsoever.

It's not just CCD that kills bees, other things happen which are very difficult to diagnose. That latter behavior also is what makes this really difficult, if there's no bodies to look at, it's really difficult to figure out what happened.