our house was built in the early 2000s. It has an awning.
Why were they forgotten? Probably because manual awnings suck, and once extended if it's windy, it's a rather fun time having it out.
Other than that, they're pretty good. I actually plan to experiment with passive building cooling using a similar technique, instead of an awning, it'll be a diffusion sheet of light fabric to block direct sunlight exposure to the walls, hopefully providing a decent bit of cooling, but naturally, i have to get around to testing it in the first place.
Awnings don't have to be a piece of fabric flapping in the wind. Wood, metal, extended roof overhangs, a deciduous tree, really anything that provides exterior shade to a window will be quite effective at reducing interior heating.
If you want one that retracts then fabric is probably the best option. I guess you could have a hard material that's made if panels that slide over each other, but that'd likely be a lot more expensive without much benefit. Alternatively you can have the vertical metal covers that extend and retract.
it's meant to be temporary and easily replaceable, the idea is to put it up during the summer so it blocks most radiate heating of the building, and then take it down throughout the rest of the year so you can still get a good view out the window.
I could also do dedicated window awnings, or retractable ones, but that's not my style. But yeah you have a good point. I was thinking about a different kind of awning initially lol.