I think YouTube's success is mainly that they were first, there were always free to use so there was no reason for anybody to look elsewhere. It's hard to compete against free and established services. You basically have to find a killer feature (and hope that the established service will be slow to copy it) or pay people to do the switch.

>Not everyone wants to be on the Internet's sewage system that's YouTube.

Yet basically everyone is. Content producers want to reach their audience, viewers want to find the content they care about.