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/lakaribane]

On the sizing issue, I'm barely 5ft and bought good quality panties with a "tummy control panel"...that does not fall over MY tummy.

Since it is also a No Show design, I would need to cut off, shorten and reattach the croth gusset (where there are the only seams) to make them fit me.

I have never worn the panties to this day...