but this is functionally the same thing. whether the user is an idiot giving you 100% of their mental capacity, or a genius giving you 1%, you have to make the same decisions when you're designing a product. "Users are stupid" isn't necessarily a judgemental thing meant to demean your users, just a reality that you have to accomodate the people who are going use your product in a way that's indistinguishable from a stupid person.
You can't assume that anybody will remember anything they did in a previous step, or that anybody will correctly interpret the label on a button no matter how clearly you think it is worded, or when presented with multiple options will be able to correctly choose the one they want.