It's extremely rare that UX designers are also users of the products they develop. Maybe they use Figma or the order entry of Amazon even if they don't work for Figma or Amazon, but who of them is going to use again the order entry form for Random Customer N after they started working on the registration form of Random Customer N+1?
My GF is a designer and she always says that the problem is that nobody test anything. I've been helping with a project for her client and pretty much everything went on the fly.
I was able to spot obvious flaws in the design, she agreed but said that she had no time and such is life.
