I got this sense as well, particularly from the section about assertions. Most of the use cases they describe (e.g checking function arguments and return values) are much better handled by an expressive type system than ad-hoc checks.
But that last 10% of checking may be really hard to encode in types. It may be especially hard to do so in the language that you want to use for other reasons.
In the first place, in order to post to StackOverflow, you are required to have the copyright over the code, and be able to grant them a perpetual license.
Obviously I cannot show the code base, but when I pick a pre-existing solution from Stackoverflow or elsewhere—though it is quite rare—I do add a comment linking to the source: after all, in case of SA the discussion there might be interesting for the future maintainers of the function.
I just checked, though, and the code base I'm now working with has eight stackoverflow links. Not all are even written by me, according to quick check with git blame and git log -S..