I think steem has the first mover advantage and will be hard beat when it comes to social media blockchain projects. If steem manages to reach a critical mass of users it is going to be almost impossible to dethrone it in the near future. Longer term im certainly a lot less sure, what is going to happen. Blockchain in general is still such a young technology and we dont even know if it is here to stay, or if it will just pave the way for new technologies yet to come.