They will come and go based on the vagaries and vicissitudes of fashion. Social media websites and apps are not going anywhere. The price of computing is will continue to go down and the world economy will keep growing. Billions of more people will be coming online in the next few decades.
User interfaces will change. Virtual and augmented reality will be a bigger thing in the coming years and decades than now. Social media apps will make use of VR and AR much more than today. The advancement of AI will lead to more powerful algorithmic curation of content. The social media apps of the future will receive feedback not only user actions on the platform but from the state of the user via cameras and sensors collecting data and modeling the state of the of the user utilizing advanced AI. Facebook has already filed patents in the field of algorithmic emotion detection from data gathered by the phone camera.
If this is starting to sound like a dystopia to you, I'm with you. The amount of data gathered by social media giants about our lives is staggering already but the future will be something else. With VR and AR tech we will invite them literally into our bedrooms: imagine wearable computers coupled with tons of sensors integrated into eyeglasses, clothes and everywhere.
I thonk that we are going to definetly see a shift towards more incentivised and decentralised social media. This is going to take many, many years, probably atleast a decade. There are still millions upon millions of people who use social media like Facebook, Twitter etc without a clue about how much data these companies collect and share about us all! Combined with the fact that theyh are becoming more and more covered in ads I think that over time more and more people will migrate towards decentralised social media, where there isnt any incentive to track us and our data.
'Traditional' social media is still the norm for so many people as a means of being 'connected' with each other. I admit I still use Facebook from time to time as a way of keeping contact with family, because that is the medium they all use.
As we are seeing with the newest dapps on Steem now they are often incentivised and offer people a reason for using them - rewarding the key asset, the users, rather than just using them for their data. I think this will continue and we are going to see more and more great dapps and people migrating away from the current system.
I hope the future will be like here in steem blockchain. It is a great model for interacting with community and even get rewarded for it.