I was 20 years old more or less when I learned that most of the world does not in fact use these I was chatting with a few british friends and the topic came up, and all of them only had curtains. As a Mediterranean (Like you I assume) they are everywhere that I didn’t even think of the possibility that other places don’t have them.
They are very useful but their downside is definitely isolation. In all the houses I’ve been, cold or heat always comes through their crevices. Sound isolation is also not great.
As soon as you asked the question, I realised that this is a peculiarity of the constructions, especially in the Iberian Peninsula, which is why @hatsnp has also had this anecdote.
My version using darktable (20230409_0109.CR2.xmp) and then a custom film simulation (also just made a post to explain better Spectral film simulations from scratch).
High saturation edit with data from Kodak Gold and Endura Premier consumer paper.