Once upon a time I used to live in libraries to make any kind of progress on certain problems. Then Google arrived and my library visits reduced drastically. Yet libraries still stand. And I still head there whenever I need some peace and quite. Something like that will happen with StackOverflow, Wikipedia, Quora,Reddit and even HN.

The difference ist that libraries are vaults of knowledge usually operated by governments to ensure access to the public.

Of all the examples you named only Wikipedia has a mission that is comparable to a library.

All the others will probably perish and exist as datasets you can buy, just like some social networks of yore.

To what extent did Stack Overflow think about destiny of Stack Overflow?