(2) It's only likely to attribute if it quotes verbatim... Just like a human. when I tell someone I learned that Array.map's second parameter passed to the callback is an index to the value just pass, I don't add "And learned this on Stack Overflow from user gtriloni". It's just knowledge that I learned.
The only time I'd attribute is if copied a snippet of code or a paragraph to quote in a blog post. For me at least, that almost never happens. It take the knowledge I learned and apply it to my own code. It's rare if ever there is a something on S.O. so useful that I copy it verbatim.
An LLM is not a human. It is a tool operated by a, in this case, for profit entity. It has no human rights, but its operator has all relevant legal obligations.
If it was, as you say, “just like a human” in relevant ways (think, feel, have self-awareness, etc.) then it would effectively be a slave subjected to extreme abuse.
Either it is a tool that generates derivative works at mass scale for profit and its operator should be liable for licensing/attribution violations, or it is a conscious being and we should immediately stop abusing it. Pick your poison.
OpenAI could integrate StackOverflow the same way.