The traumatic revelation is that all my vain attempts to keep my inbox under control by filing emails in folders are actively making me less productive. It apparently takes up 10% of the time spent on emails (ie, 10% of our lives) to do this filing. Worse, apparently our filing efforts do nothing to improve the speed at which we can re-find emails when needed. Shockingly, those inbox slobs who just leave everything in situ and search for what they need actually find what they are after quicker than those of us craving order.
Obviously, do what you find best, but as someone who has never since 2004 when I got my Gmail account used any folder system for my emails, this study makes me feel better about my choices.
For what it’s worth, one of the things I like about Hey email is that not only does it not center around folders/labels, but it suggests that many emails don’t even need to grace your inbox. If I need something to read, I check the feed, and if I need to find something, I just search for it.