I've been enjoying this series but this specific claim is wrong.

Indeed, I learned from reading Dennett that quite a lot of our characteristics are purely accidental, and others are non-functional byproducts of actually useful features, which he calls "spandrels".

Dennett's point is quite different. It's that even though evolution is random and blind and has no intention, and there are many accidents that have no survival value, that arguing from the "intention" or "meaning" of an adaptation is not necessarily false.

As an example, Dennett believe that the statement "humans sweat in order to control body temperature" is a reasonable thing to say even though no one designed it that way.

I've read most of these writers, and overall your accuracy is good. Accept claps.