I wrote a post last week about why I shared something on Facebook and not on Steemit. You might find it interesting. People still desire to post selfies, cat photos, pictures of their dinner, what they did that afternoon, etc... and I think Facebook, Twitter, and Instagram are great for that. Medium? Reddit? No so much. Same goes for Steemit, I think, but here's the key:

The Steem Blockchain can be whatever we want it to be.

There are already projects going on to make Twitter clones, as an example. The database is there for anyone to innovate with and any new user interface "skin" can be put on top of it. In the future, I imagine each industry having their own Steemit clone which caters to their market vertical, complete with custom UI and plugin interactions.