Encryption provides a good way to keep secrets. This has nothing to do with privacy. Privacy is minding my own business without anyone watching me or judging me.
If you need to rely on encryption to protect your privacy, then you have very little privacy, because everything that is not encrypted can be snooped on: where you are, who you talk to and about what (because GPG doesn't protect the username and subject), who are your friends (because you can't trust them to encrypt properly).
If you want to escape surveillance, encryption is just one tool. What you really need is good opsec habits. See for examples http://fr.slideshare.net/grugq/opsec-for-hackers