The idea of a blockchain-based social network is very attractive in terms of openness, lack of censorship and content monetization without any middleman. For this reason, a number of projects have been announced in the last few years which could be potential competitors to Steemit.
A recent Nasdaq article mentions a few active projects (Steemit is mentioned first!) One of them is Akasha.
Their team has strong credentials (Vitalik Buterin is an advisor). Some time ago I did download an application containing their Alpha release. To me, a non-technical user, it feels bulky and slow. You need to download a client, then synchronize with the blockchain…argh! Let´s say that they are not ready yet to compete with Steemit…
Synereo is a similar story... great ambitions, great technology, but…not there yet. They recently announced Qrator. Very nice on paper…we'll see how it goes…
Yoyow is a China-based project which was announced recently. According to them: “Yoyow will become the Blockchain version of Facebook, Quora and Zhihu …Compare to our competitors (steemit, decent etc.), yoyow has many advantages: Firstly, the yoyow Blockchain is built on Graphene framework that provide fast confirmation speed, and use a new consensus algorithm – PoF (proof of flow)”. Clearly, it sounds interesting.
Last but not least, I've come across the Ubermensch project, which seeks to build a “decentralized LinkedIn” aimed at the crypto business community. They propose, among other things, to decentralize business processes by performing e.g. collective due diligence on new projects. Needless to say, this also sounds quite interesting.
Steemit is well-placed to capitalize on its incumbent's advantage here, coupled with possibly the best blockchain technology around. As long as sign-up bottlenecks are kept at bay, I believe Steemit is here to stay and rule :-)