I've probably read more fanfiction than other material over the last several years. (Like everything else, there's a
lot of very-low-quality stuff, a fair but comparatively tiny quantity of pretty good stories, and a few absolute gems---in the Harry Potter fandom I've run across one or two that I think are better than the original except for needing readers to have read the original.) One primary reason is that the "get the characters sooner" category of fanfiction is better for "comfort reading" than the original (at least in the case of
Pride & Prejudice fanfic), but also because I've accumulated a digital library of fanfic stories that at one point or another I saved or bookmarked, and even just sorting through them to see what's good and what's less so takes time and attention.
The world in which my stories are (to be) set began to be conceived (when I was eight or nine?) as the answer to a fan-fic-ish question ("what happens to the place where Father Time had been sleeping when things are remade into New Narnia?"), but quickly far outgrew and basically cast off that beginning. Since then, while I've occasionally had ideas that I wish
someone would write fanfic about, I've never felt an impulse to write it myself ... except maybe for Aubrey Hansen's as-yet-unwritten Erde

(Alternate history settings, on the other hand ...

)