For search engine I'd suggest duckduckgo, it's far from perfect but I don't see any other viable alternative, if anyone knows anything please let us know.
For messaging I would suggest Signal. The problem there is that most people don't know of it and they won't ditch whatsapp to go on something that their friends won't be on.
That's the same problem that a new social network is going to face. I think it's safe to say that if even Google with all their capital couldn't make it work, then it's going to be extremely difficult to find investors to bet on a random guy's idea. Facebook with all the shit it has been and done has almost 2bn users, how are we going to convince even 5% of them to abandon it for something new without anyone they know there?