I dunno. I think it depends on the fic, and the fandom, honestly. With me, I seem to flit between different creative "modes" as I can them. When I'm in Binge-Watch Mode, like I am now, all my creative energy goes towards whatever I'm binging, whether that's making icons, writing an essay series, looking up fanvids, whatever. When I'm in Writing Mode, I can churn out a decent word count on a semi-regular basis, but that is unpredictable and very hard to get back. Or if I'm in Reading Mode, I'm just consuming book after book or fic after fic, and have a read hard time producing anything myself. It's very rare for any of those to overlap.