On the hard outside shell, LBRY and Steem look as though they are directly competing with each other. Both are vying for the attention of the crypto early-adoption content creators and watchers who are looking to reach out to other means than the typical centralized social media platforms (facebook, reddit, Dropbox, Instagram, and the like). Looking at it this way, these two could be Periscope vs. Meerkat 2.0.
All this said, in my opinion it seems as though the two could in fact be supplementary pieces to a larger puzzle much like the way we saw Youtube and Facebook integrate well with one another circa 2012, for instance. When you see the way LBRY and Steem are starting to reach out their tentacles as they develop more and more, it is easier to say how this may become the case.
I think the two kinda look like Instagram and VSCO right now more than anything. The way that we have seen VSCO be a supporting piece to Instagram over the past 3 years is great for leveling up personal brands. Now, I think Instagram stories are evidently killing off the vsco link in people's profiles and as we shift in the way we post content it will disappear entirely. However, the pattern is the same here. Steem, with platforms like DTube and steemit is acting very much so like Instagram in the sense that it is the mass outreach and collection of data to make up a platform where you can search for any variety of topics for content and find results. And so, that makes LBRY the complement to more narrow content much like VSCO. LBRY runs off of its own blockchain and currently supports uploading of any file widely used file format, something that steemit/DTube currently don't support.
LBRY is like this mass collective that is currently acting more as a place to store files for any and everyone to view. Steem platforms are acting more as social outreach and communication methods used for sharing and commenting on content. This is how I see the two working together. Steem platforms will be the place people go to do their research and due diligence on topics, brands, entertainment, you name it. It falls in the same category as the other large social platforms that enable you to find the content that you want to see. This means that for the two to work together, ideally the original content, protocols, or files that you create are uploaded through LBRY and pushed out through Steem platforms. In my opinion it is a lot better way to get your money's worth out of what you are creating. LBRY has a much simpler monetization method than steemit/DTube and you can also monetize on multiple platforms this way. For example, you can create a 3D print for a soccerball and upload it to LBRY, where people can get access to the file for 1 token (or LBC). Then you can make a tutorial on how you created the print and post it to DTube for more brand awareness. At this point you can monetize the "how-to" video on DTube and drive people to your LBRY file so they can pay in currency to download the file and follow along. Then you can push this whole topic to steemit to get the most outreach possible, and if you are good at pushing content, you can monetize that blog post as well.
These are just my speculative thoughts but I have analyzed this for a while, and it is the way I see it going. Please let me know your thoughts if you have any input.