I expect there's loads of old FB posts and Tweets linking to Steemit that will never get updated. I did look at my old Blogger sites and just updated some links there. I don't expect that will make much difference.
I think if you add up Hive.blog, peakd, ecency and leofinance they may still get less visits. They do dilute the brand a bit and some hide the fact they run on Hive.