I think I might have used the wrong (or at least, a somewhat inaccurate) word. I was thinking in Spanish, where "decadencia" just means "decline", and just translated literally. But in English "decadence" carries extra connotations of luxury, pleasure, etc. that I just forgot. What I meant is that it's one more sign of the decline of the West, but I didn't intend to link that decline to hedonism (which is a very Anglo-Saxon/protestant thing to do, hence probably the different connotations of the word in English with respect to Romance languages, but this view is not something I really adhere to).

Anyway, I would argue that "being grand" is not useless, and this kind of monuments do have a value. From a shallow point of view, they bring lots of tourism. But apart from that, they have artistic, cultural, symbolic and, in some cases, religious value. They attract people and make the cities they are in more desirable. So I do think not building them anymore is a sign of