I think that would be awesome to build something on Steem if you can find someone with the skills to help you do it. I would totally be an advocate for that. I prefer to use my own images, but that isn't always possible. I think people fall back to Pixabay because it is free, but I would not be opposed to using something built on Steem and donating .5 SBD here or there whenever I needed an image. I had read a while ago about a block chain that was doing something like this for image licensing, but I don't remember the name of the token and I am not sure if anything ever became of it.