Generic phishing emails are the most common type of phishing attack. Attacks like these are common because they take the least amount of effort.
Hackers take a list of email addresses associated with PayPal or social media accounts and send a bulk email blast to the potential victims.
When the victim clicks the link in the email, it often takes them to a fake version of a popular website and asks them to log in with their account info. As soon as they submit their account info, the hacker has what they need to access their account.

In a sense, this type of phishing is like casting out a net into a school of fish; whereas other forms of phishing are more targeted efforts.