I think why solarpunk seems to come into vogue is that it is often displaying so much more livable and humane cities than we have right now. The same goes for its ornamental design that contrasts so much with the clinically sterile look of products and designs nowadays - especially the ones that are coming out of the Silicon Valley at the moment (UIs with grey-on-white designs and no embellishments, the look of voice assistent devices, speakers, watches, SpaceX' flight suits/launch towers, Cybertruck,...).

PS: The spelling is actually "Zeitgeist" if you ever need to search for that (even though I would assume that search engines would deal with the typos just fine).