I won’t address everything because it’s a lot of text, OK? (I did read it though.)

I think that it’s more accurate to say that reasoning is a “tool” that you use to handle knowledge. And sure, without knowledge you aren’t able to use reasoning, but sometimes even with knowledge you aren’t able to do it either - we brainfart, fall for fallacies, etc.

Another detail is that ignorance is far more specific - a person isn’t just “ignorant”, but “ignorant on a certain matter”. For example it’s perfectly possible to be ignorant on quantum mechanics while being informed on knitting, or vice versa. In the meantime intelligence - and thus stupidity - is split into only a handful of categories (verbal, abstract, social, etc.).

To someone who knows more than us, they’d consider us stupid.

They’d consider us ignorant. At least if following the distinction that I’m emphasising.

When we talk about people being stupid or smart, we’re just reducing that complexity so we can make simplistic insults that make us feel better about ourselves, but ultimately aren’t saying anything meaningful about the human condition.

Not necessarily reducing it but I get your point, given that I think that it’s simply easier to talk about ignorance and stupidity as behaviour than as something inside our “minds” (whatever “mind” means). And in both cases it’s behaviour that we all engage; some more than others, but we all do.