Steem definitely looks poised to become the mainstream's gateway coin into crypto.  However, once people are into Steem, I think the value proposition for Bitcoin (and others) will become much more accessible, due to the ease of exchanging digital coins (relative to fiat).  Bitcoin is currently the most-trusted, defacto "reserve" digital currency.  It may never have the capacity required to support worldwide retail or a social networking site, nor do I think Satoshi intended it to.  Equally, Steem is social-media platform (and shopping destination?), not a place one would put large amounts of their savings for purpose of insulating themselves from various kinds of economic disruptions.