It doesn't really, as you can see in their traffic numbers. People are not stopping to use it because they dislike the platform (Most people would not even be aware of any moderation criticism, especially if they are just readers).
People are not using it any more as any AI assistant will give you the answer in seconds, perfectly adapted to your use case and with an easy way to ask follow up questions.
Exactly.
StackOverflow was always just an "answer machine".
They wanted it to be a community, but it never was.