I have a simple theory for this. Any time this question is asked, people point to cultural or moral reasons (e.g., the declinist view of Western society or some other mumbo jumbo). IMO, this is only because they lack insight into more important structural reasons, such as politics, economics, or institutions. Culture is certainly an important variable when discussing social outcomes. But it's often a black box used to explain variation that can't be explained by more important structural factors (and sometimes, culture emerges from structural factors!). And thus, when people lack insight into politics, economics, history, or institutions, they conveniently wave their hand and say "culture." I have a simple theory for why we don't build stuff like this anymore: patronage. These buildings didn't just pop out of the ground. They were funded through imperial or aristocratic patronage. That means they were funded by the state, church, or tycoons (e.g. New and Old Money). This specific building below is Palais Garnier opera house in France, designed by Charles Garnier and built at the behest of Napoleon III. At the time, it cost about 36 million francs, which I believe is about $500M today. It took about fifteen years to build. The French state was fine with funding it because it projected imperial grandeur. Certainly, we have expensive architectural projects today. But a lot of the money goes towards meeting code (e.g., structural integrity, seismic requirements, sustainability requirements). Labor is also more expensive now because you can't just exploit people (at least when there are unions). Land might also cost more, depending on the location of the project. Building something like this today would cost considerably more than $500M. And who would fund it? Can you imagine if the US government — currently already undergoing austerity cuts — spent something like a billion dollars on a building that only people in a certain city could enjoy? People would rightly lose their minds. You can't build something like this because 1) public scrutiny is higher, 2) we vote, and 3) this is seen as wasteful spending. Of course, you could get billionaires to fund it. I have lamented that Jeff Bezos buys crappy designer dinner suits instead of using bespoke tailors, but some people lost their minds ("who cares?" "he's rich" or "he can do what he wants"). I'm not suggesting that we make a law preventing Bezos from spending money how he likes. But thus far, he has poured about $15 billion into Blue Origin. Can he spend $1 billion on building beautiful public libraries, theaters, or museums? They can be in this Beaux-Arts or Baroque architectural style, if he likes. People ask "Why did humans stop building like this?" They should follow-up with: "How were these projects built? Who funded them? And why don't more billionaires today support artisans, craftspeople, and public work projects?" FWIW, I have made this argument before and if you'd like to read it, you can check out this thread: xitter.cf/dieworkwear/status/194…