> In this kind of web, it would also be quite possible for a single developer to run a site as big as Youtube without needing tons of up-front cost. Bandwidth is free from the perspective of the site developer,

How would that work? Blockchains are far too inefficient to host video files and nobody is hosting that much data for free so you still need to set up a paid hosting environment or learn why P2P video hosting has failed every time it's been tried in the past. You can charge people to host their video, at which point you'll learn that it's really hard to compete with ad-supported hosting because the number of people who say they want to pay up front for their stuff and actually do so is a rounding error of the number of users a major video site will have.