I think there probably are a lot of sites plugging into steem, however they have not really expanded beyond steemit.com supporting sites. @meno gave a list saying what I see. I don't have a problem with it being in beta for two years... coming back after being away a lot of that time I can see it did some good, not going to quantify it, but I see changes and hear of others on the way.

Agreed that aside from steemit.com supporting sites I do not see much of anything being built on it.