> Modernism is the act of using cheaper resources and more standardized/cheaper methods of production.

That's how they sold it, but it's not true. By the end of the 19th century, all the building ornamentation that you can still see in European capitals, had been stadardized and was mass-produced, while the construction techniques using brick and mortar had been further refined, yielding building designs that were cheap to construct and easy to maintain.

Modernist buildings were, at the same time, more expensive to build and less durable because of the reinforced concrete which has a much shorter lifespan than stone or brick plus mortar. The only advantage they had was that of increased height, but that was only an issue due to the restrictive zoning in Anglo countries. Without NIMBYism that pushed towards sky-scrapers, NYC could well have ended up like Paris: replacing 1-3 stories buildings with 8-10 stories, but allowing mixed commercial/residential space everywhere.