I think this has a lot to do with people's mentality. Social media is basically an outlet for people to vent out their frustrations in hopes that they'll see someone that might understand just exactly what they're going through.
Add to that the fact that alot of people are more interested in creating false images of themselves online than in reality and you'll begin to see why people are so obsessed with social media.
The advent of social media provided an escape for people and a means for people to connect with other people around the world, but this slowly changed from connecting with others around the world to being worshipped by people around the world. It became a race to see who could amass as many views or followers or likes or even upvotes as the case may be.
Social media has made us feel like we have to share our daily activities with people online because our online life is more important than our real one. The fact that you could get a "you look good" or a "great job bro" online but not in real life also adds to the reason why people are so addicted to social media. Everybody wants to be appreciated and everybody loves getting complimented, if you can't get that in real life then the next best place to get it is on social media.