Are social networks dead? If yes, what’s next?

Emphatically NO.

Perhaps FB etc, will die or morph – who cares.
BUT! People are fed up or corporate PR and advertising and tuning out the standard corporate message in favour of personal recommendations. This is where social media comes in. In Asia, reputation (or ‘Face’ in China) is all important.
Asia is a fast growing market and word of mouth is how their society has been built. Originally, developing countries did not have TV and print media to persuade them and word of mouth was how businesses were built. Shoddy suppliers went out of business fast.
Fast forward and these countries still rely on reputation, more so than the West which built brands then trashed the brand value by getting the product made on the cheap in Asia.
Customers (especially younger ones) are wise to this and are also more niche oriented in a saturated market so they seek quality instead of Walmart rubbish and want the recommendation to come from a trusted source not a junk mailer catalogue.
So ‘Trusted’ social media is the upcoming thing. Ello is one example.
FB has become another brand which ‘sold out’ to the capitalist corporate agenda, so the young consumer has left the place to their parents.