This is about body shape, I’m short waisted so dresses fall on my waist, but I’ve very slim hips. Like a rectangle, so if it’s a column type dress the hips can be a couple of inches to wide.
ive really long legs for my height, which is just a half inch or so taller than you, and pretty much no regular length trousers fit me, most are too short.and flap round my ankles,
I think they simply have to cut for a body shape and when you buy off the peg then you’re either going to fit that shape or not.
so for example, me and em fit me perfectly, like they were cut for me, as does Reiss, but markies just don’t work, the body is too long for me, waist either too tight, and hips too wide, or hips fit and waist too big. If the clothes were better quality I still couldn’t shop there. Reformation tends to cut for a more pair shape so I find their clothes just too big on the hips,
so you need to find the brands that works for your body shape. There simply is no way to go into every shop and it’s always cut for our bodies, as our bodies are so different.
id guess you’re long waisted, which is why you’ve the issue you have.