I was missing one aspect as to why so many of us are drawn towards cottagecore, which is that the return to a more simple life means a return towards more connections with non-humans. People and their different non-human allies (plants, animals, fungi) go way back and recently we've lost touch. We don't miss the sourdough for aesthetic reasons. We miss the sourdough because it's an old friend.
The world we have created is entirely human-centric, and now we feel alone.
As to the aesthetization and commercialization of subcultures - that has always been a risk and is in no way limited to stuff liked mostly by girls. As soon as a subculture gains a name the vultures arrive. Just waiting for the new range of solarpunk softdrinks to be available in my local store tbh.