I believe it should have a great future. There a few things that need ironing out but that can be expected with a new platform. Many are feeling down because of the drop in price, which has very little to do with the Steem platform but with sentiments towards cryptocurrency as a whole.
It is possible that Steem could be unseated. At the moment nothing seems close, anything on EOS looks like a big unknown. Medium is quite popular but there is very little money to be made. There is another platform, that uses Bitcoin Cash but I can't remember the name now. There is also lunyr, which looks a little like Wikipedia I believe.