Social networking is just one entry in the long list of Google's failures, many of which were successfully executed by smaller companies:
* Chat. Google has tried like 4 or 5 different times to do chat and ultimately lost out to the likes of WhatsApp, Slack, Messenger and others.
* Location/business Reviews. Despite having Maps, google still has yet to really come close to unseating Yelp in this arena.
* Wearables. Google Glass completely failed. Android Wear is well on its way to the grave. Fitbit, Apple and Samsung have all succeeded in wearables over Google.
* Augmented Reality. Remember Google Glass?
The list goes on. My point isn't that Google can't do anything right — that's obviously not true. What I'm saying is that Google trying something and failing isn't really a good argument against it being a viable idea.
Facebook's brand is ailing right now and I think there's growing concern about the way Facebook has been optimized to dominate the user's attention. There might be room for a social network that tries to be something much more minimal than what Facebook has become.
When google tried to go push '+' they needed the people to forget about the data, messages, pictures and everything else that was on facebook. That burden was a bit too much.
GDPR requires facebook to provide users with their data in a machine readable format. So that competitors could write migration scripts and there would be no such lock-in. Makes it easy to switch platforms and bring some competition into the space.
Art. 20 GDPR Right to data portability https://gdpr-info.eu/art-20-gdpr/
There is probably FAR more opportunity to building a Facebook competitor than a newspaper competitor nowadays.