My biggest gripe with Postman is the horrible theming. Except for light and dark, 0 control over the appearance of this app that I have to look at for hours almost every day.
My biggest gripe is that its design leads to accumulating long list of slightly different "tests" whose purpose is soon forgotten. I suppose there are better practices that can stop that, but the path of least resistance is "copy, edit, run," and so a huge pile of meaningless garbage accumulates.
