It is okay to be worried and the question is how helpful is it to be worried? What makes Steemit superior already to Facebook is the potential for posts to be found in Google search which already brings many users here automatically and will continue to bring even more as the website grows. I focus on whether I enjoy making a post rather than how many people read it because no number is ever enough for readers! Not a lot of people read my early Facebook posts or most of my posts for the next ten years. Not all of us need a huge audience! Just a few friends investing a bit together can easily earn hundreds of dollars a month just voting up their own posts here. For example, if my wife and I each started from $0 and invested about $2,500 to buy about 1000 Steem each, we could literally vote our own posts as you voted your own comment up for about $5 a day at the current prices or $150 a month. Not even accounting for a price increase, that is $1800 a year back on a $2,500 investment. That is why I am not worried!