Its really a bad practice to publish the same content to multiple places on the web, search engines will penalize you for doing so, and they wont tell you either. Google drops the rank of content republished multiple times. I noticed a lot of people do this on DTube, reuploading their entire YouTube video libraries, but its not a bright thing to do.

People need to learn proper SEO practices and how search engines work, otherwise they're just shooting themselves in the foot. Content posted on Steemit is indexed by Google search, and if the content is a duplicate, Google will devalue that content as a whole.

On the other hand, its always a good thing to diversify in ones content strategy by creating content on multiple platforms. I plan to continue posting videos on both DTube and YouTube alike, but I also plan to keep that content unique.

But DTube has problems it seems. Videos there don't get properly retained, often being deleted within days of uploading. I think its going to take some time for DTube to get the issue of video retention right. Till then I'm backing off from publishing a lot of videos there. A lot of my videos no longer will play, and I'm seeing the same issue with others as well.

The better solution to sharing the same videos from YouTube elsewhere is to create a blog post on Steemit and embed the video in the post, adding some new images, and a more thorough description with new context. Then its considered unique content again by search engines.