In current times almost all of us have been driven online to shop. For most things, you can get them online, but what I’m getting at is clothing (because it’s my trade).
They design around that perfect body, & they call that the “sample”. They make the sample usually very little & trickle down from that, to the bigger sizes.
Each brand evolves in a different way. They may have started out from a different point.
For each brand, each has a “model” body, which most people can’t fit.
Each brand has its own DNA, some grow in different ways, some have a different starting point.
Just remember that their is no fitting rooms so you’re stuck with what you’ve bought.