I may be wrong, but if each poster had an IPFS server with their videos, then videos would not disappear. This was a good video: An idea that I think would work to keep videos avaliable is thumbups would

Check out this post:

Thanks for pointing me in the correct direction. I successfully uploaded to DTube using ubuntu and openshot (target MP4(h.264) Video Profile HD 1080p 29.97 fps Audio ac3 44100 192 kb/s)