I don't have an awning...yet. But this has me thinking about it.
For shade I usually just put my chair on the shady side of the camper -- at my home latitudes the sun is never overhead, usually at a
large angle from overhead, and the camper is tall, so there's usually camper-shade. But near the summer solstice and/or when I take a big trip and head for the Deep South (anyplace south of Reno) it might come in handy.
For protection from rain: Hmmm....I usually
avoid rain -- that's what the desert is for.
Usually when I'm inside the camper to avoid weather it's because it's
cold, not because it's wet. But if I found myself in an area that's rainy and yet still warm enough that I
want to sit outside, an awning might come in handy. Maybe if I lived-in/visited-more those states that have summer monsoons/thunderstorms.
As for gear storage outside in the rain: my chair is the only thing outside that I'd like to keep dry -- the graywater container and hole-digging shovel don't care about being wet.
I think for me an awning is an accessory that I don't
need -- obviously, since I've used my camper for >8 years without an awning and without yearning for one. But maybe it's the kind of accessory that I'd find myself using (at least once in a while) if I had it.