DING DING DING!!!! You are 100% right. First and foremost actual fashion(especially high fashion like haute couture) DOESN'T cater to fatties. Their largest sizes are usually M's (but on the smaller side not your typical M). Even  pret a porter(day to day) clothes that are designer, designers refuse to cater to fatties as well. Additionally about 99.9% of the clothes they make would look warped and hideous on some monstrosity unlike a shitlady or lord. They can be commissioned but it takes an exceptionally large bank account to do so. Even with companies that DO cater to fatties, they don't have enough creativity to make nice designs. Even if the clothing WAS designer, fat people are just overall incredibly retarded so it would be hard to understand what actually makes you trendy and fashionable.