From what I know about PGP, it's built on the concept of Web Of Trust, where trust is transitive. PGP belongs to public key infrastructure, and its main purpose is to provide ground for the authentication of public key, i.e. some public key truly belongs to a person who the key claim to belong. Authentication here is implemented by me using my private key to sign someone's public key, in order to authenticate they are the true owner of the public key. Since people who know me, and my public key in person, can verify my signing using my public key, then they would automatically 'trust' someone's public key which I signed. This poses a security issue when I mistakenly believe the key belongs to someone and I sign it. Then, my web-of-trust would automatically trust that malicious guy.
Since people in the web of trust usually know each other in person, which makes it very difficult to engage in, thus preserving some degree of privacy within the group.
So, coming back to your question, it all depends if such degree of privacy is needed, a group-level privacy, when deciding whether or not to use PGP.