Hi, the developer, @heimindanger, points out in his blog post annoucing the 0.2 updates the following " The 25% fees will cover the development costs, for a couple of months, then once the project is solid and we stop working on it, paying the fees will only remain as a defaulted option."

It goes on to read "The total earnings of @dtube can be seen at https://steemdb.com/app/dtube/earnings (built by @jesta). As you can see, we are averaging 200 SP per day. That is a lot of income and it is enough to find a competent second developer as well as a designer to help this project going faster. I am already in the process of interviewing and will pick wisely."

In his initial blog post revealing DTube, the following is said in relation to the costs of hosting the content "I have recently created the @dtube account. This account will be used to collect 25% of the DTube author rewards. 10% of these fees will be used to pay for long-term storage of the files on IPFS Store. The rate is $0.044 per GB per month. So, for example, let's say you upload a 100MB video, that earns $10 rewards, then $0.25 will go to @nannal and ensure data redundancy for ~57 months. Once this time is passed, users will need to either pay themselves (crypto accepted of course) to keep the files being seeded, or seed it themselves directly on their own PC and connection."

Now in relation to why someone would want to use this platform, I do urge you to read his blog posts: https://steemit.com/video/@heimindanger/introducing-dtube-a-decentralized-video-platform-using-steem-and-ipfs. Essentially, you post whatever you want and as long as you are around, that content can't be controlled.