I think, Steem is spreading faster than Bitcoin, because Bitcoin as a token did not have any usage other than trading, where as steem has lot of potential in terms of no of dapps being developed and incentivizing people. Today, its easy to just get engaged with these dapps , even though, someone is not a regular content creator and earn few steem daily. And apart from that, these dapps have their own tokens as well, which is like a add on. So if it took bitcoin to reach this level in 7-8 years, then probably steem is going to do that in half of the time, 2019 may be the year when it will start spreading rapidly.