I don't see SO and software blog as interchangable things at all. SO is for seeking answers for specific problems, while blogs are for entertainment weaved with learning.

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.

I dunno. I know it makes me an enemy of humanity and all, but LLMs have mostly replaced Stack Overflow and dev blogs for me. A dialog with something that writes well (or can take a totally different swing at an explanation if the first one isn't so good), has expert-level knowledge, and isn't egotistical. But maybe most of all the dialog part.

Anyway, I'm learning so much more so much better than I ever have before. Turns out the ultimate slop tools are also the ultimate learning tools if you use 'em right.

Do they? How would it be different?

In 2021 maybe.

Today LLMs have completely replaced the original role of StackOverflow.