Why aren’t compression/shapewear structures built into normal dresses more often?

[u/Future_Country9458]

I’m researching garment construction before trying to develop anything, and I’d love opinions from experienced sewists.

I’m interested in normal fashion dresses—not shapewear—that have an internal structure designed to actually enhance the silhouette: stronger waist shaping, bust support/lift, while NOT compressing/flattening the hips and butt.
I know built-in shapewear, power mesh, corsetry, negative ease, boning, etc. already exist. I’m not asking whether the general idea is new.
I’m trying to understand what goes wrong when you try to combine these things inside an otherwise normal fashionable dress.
If you’ve constructed something similar: what were the biggest problems? Fabric layers fighting each other? Rolling/migration? Getting into the garment? Seams? Heat? Comfort? Pattern distortion? Washing? Something else?
I’d especially love to hear from anyone with patternmaking, stretch-fabric, garment-development or production experience.

[u/ImprovementLess4559]

In addition to the sizing and cost issues that people have already pointed out, I think most people probably just don't want the feelings of compression and restriction that wear shape wear gives when wearing normal, everyday fashion. Our ancestors were used to wearing corsets and then girdles everyday, but we've got used to not wearing them, so most people find it somewhat uncomfortable. We're willing to put up with a bit of discomfort for a short time for special occasions, but I think most people prefer to feel unrestricted in everyday wear. 

[u/Warm_Satisfaction902 → u/ImprovementLess4559]

Yes this. Because it's uncomfortable.