Just a single data point, but when I copy & paste a snippet from Stack Overflow, I always add a comment "// source: https://stack overflow.com/questions/xxx#yyy".

I both find it respectful of who wrote the answer in the first place and useful for future users of the code: the Stack Overflow answer often provides context and explanation for what would otherwise be an obscure piece of code.

Pretty darn useful if you ask me: those who want to have more information can follow the link, casual readers can skip it, and the whole process if fair to the author.

In general I'd agree that it's best to use answers just as a guide. That said, I wasn't trying to pass judgement, just ask attribution which is a best practice and often required by the license itself.