In the end, the construction industry is really a deciding factor : you only see, as a classic survivorship bias phenomena, what the best building with all the money in the world looked like, ie cathedrals, palaces, and expect every building to have the same standard today. It is not realistic, nor responsible. Cheap building for the masses have always been the norm!
I would call this a false dilemma. There are a bunch of examples in Manhattan of beautiful facades that are extremely ornate but are painted cast iron. It does not have to be styrofoam.
>I'd rather be paying for what I consider important for a building (longevity, ecology and thermal efficiency) than some esthetical addendum
First of all, I'm not even sure that modern buildings achieve these goals.
Like you are saying, you are speaking of cheap buildings for the masses. And a sibling comment talks about how people only look at the bottom line. If a building is beautiful, it is loved; if it is loved, it is more likely to remain. And a building that remains is best for ecology.
And also, buildings are not just for the owners, they are public works, and should be designed as such. An "esthetical addendum" is not mere vanity, it is an important contributor to quality of life in a city.