I work in construction for a general contractor, and yes it does cost more and developers in major cities skimp out on this. It’s called ‘value engineering’ — essentially how can we achieve the same goal for cheaper or how do we just get rid of it all together by changing the design. Most of the time it’s by doing the latter. This can happen not only with aesthetic design but also HVAC systems, electrical systems, etc.

The material to add details like this isn’t necessarily the most expensive part, its the labor to do it if you want it done right and not cheaply. We’re at a time where skilled trades are already struggling to find people and to keep/pay people is very hard. Big trends in design/construction are a factor of a lot of things all at once.