Well it’s nice to think about and imagine. But none of it will probably happen in any of our lifetimes, if ever.
If everything starts to fail, we’re screwed. But why on earth would that happen to the entire world (I’m assuming you mean all humanity)? Can you provide some possible scenarios?
The example you gave doesn’t really connect with your previous point, at least, from my point of view. The example is just speaking of everyone ditching facebook and forgetting about it possibly in favor of newer social networking sites, but the point was about indirect, unwanted restrictions of the mind. The way I interpret it, you’re saying that everyone will suddenly become retarded and all the man made things will start going down. Correct me if I’m wrong.
Human nature hasn’t changed a single bit all through our history books and technological advances. It isn’t likely to change anytime soon.