I think we shouldn't underestimate the 'social media' aspect of STEEM. Facebook is huge, and it's nearly 'only' social media. We should try to let our piece of the big 'social media cake' grow.
The communities you mentioned are actually social media,

And of course that doesn't exclude building more and more great DApps like for example Splinterlands.

Yes, STEEM is more than social media, but in my opinion social media still is an important part of it. Actually all the new DApps could recruit a lot of users from a well working social media part of STEEM.