It used to be addictive, before social media, when it was a social network. You were interacting with real people, you could meet new people, "stalk" people you know IRL, share stuff about yourself or find out stuff about others. You would try to find your crush on FB and check see if you have common acquaintances. And you would obsessively watch who looks at your page and who likes your posts. The thing that made it addictive were the actual human interactions that people crave.
I wish someone would make a site like that again!