My guess would be that a "platform" for serious video content could not be financially viable on today's internet. It would need be able to alienate advertisers over points of principle, effectively argue those same points with regulators, and field an army of capable moderators. It would probably end up looking more like a public-interest media company than a video-sharing site.

Discovering an algorithm to govern on-site activity by the general public that doesn't lift the scum to the top could be a decent start.