> And ofc the modernist rejection of any ornament; even that which is there historically, on existing architecture.
There's an ideological capture of postwar architecture departments. Talk to a dutiful architecture student and mention classical architecture, and don't be surprised if you get some eye-rolling or stock dismissals ("it's anachronistic", "it's pastiche", "it's expensive", "it's unoriginal"). People - and that includes students - tend to go along with the prejudices of their professors, both because of ignorance and because they want to "fit in".
There are some maverick departments[0], however.
> My hope is that in a future where we 3D-print buildings or construct them with robots [...] the cost difference will be marginal/nonexistend.
The cost isn't the issue. Societies much poorer than our - and we are the wealthiest we've ever been in history, materially speaking - have produced magnificent artwork and architecture. We simply have different priorities. I don't remember who it was who said this, but if you want to know what a society worships and holds in highest regard, look for the tallest building in the city.