Why is DTube Necessary and Why Should I Use it in Addition to Steemit?

So I just discovered DTube and it's a cool site. I watched an interview with the creator and he seems like an awesome guy. What I really like about him is how he seems very grounded and realistic about what he built. What I mean by that is he doesn't act like DTube is going to overtake Youtube next week and in the interview he kind of stepped in and clarified when the interviewer made assertions which were maybe a bit over optimistic for lack of a better word.

Anyhow I'm trying to wrap my head around how something like DTube or Steepshot interacts with Steemit and how as well as why I should use it?

So in the case of DTube, when I upload a video it also gets posted to my Steemit blog. Why should I use it as opposed to just posting it directly on Steemit? I guess at the very least it's not hosted by Youtube which I realize is a big plus to people but what other advantage is there to me using DTube?

A while back when I first got on Steemit I tried out another Instagram like Steemit app or program called Steepshot which was for posting pictures on Steemit. While it was kind of cool to have an app, I just didn't see what benefit it had to me as opposed to posting the photo on Steemit, especially since Steepshot seemed to be kind of glitchy with posting tags so I'd wind up having to go back to Steemit anyways.

Anyhow, I'm supportive of the project but would like someone to explain to me why I should post my videos to DTube as opposed to directly on Steemit. I also had kind of an etiquete question. Should I go ahead and repost past videos I've always posted on Steemit onto DTube? While they aren't on DTube yet it will in a sense create a duplicate post on my Steemit blog.