If the file is that poorly seeded, and therefore extremely sparsely watched, then the laptop with a broken screen in my closet can serve it to anyone who wants it.
The only reason we need a scalable system, is to handle high demand / broad appeal media and in that case, what you describe WON'T happen.
For low demand media, https off my mom's coffemaker will do just fine.
That means anyone posting 100-200 video to youtube today, can easily handle all these situation with less expense than the price of whatever camera they filmed the content with to begin with.
Youtube only exists, because us, old internet fucks, got lazy and relied on google for mail and video.