FWIW, I struggle with the same thing and this thread has prompted me to try and do something about it.

Considering that it seems that quite a few other people have the same problem, perhaps it's an idea for those of us who feel troubled about our 'digital hoarding' to collectively try and detox (at least for a while to see how it feels)? Perhaps a 'Junkless July' and a follow-up Ask HN at the end of that?