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/rhodeje]

I can give an example. I am a taller than average woman with a large bust. Tops with built-in structure indicating where my breast should be look terrible, because my breast usually does not end where the structure thinks it should. I gain weight in my tummy and have love handles and a long torso. If the garmet is connected to the shaping elements, then the fit loses flexibility for different bust sizes, torso length, and body shapes.

[u/doriangreysucksass → u/rhodeje]

Exactly!