#PeerTube has a neat opt-in mechanism in place to alleviate the fediverse ddos problem of popular videos: it's what they call redundancy. Servers that opt-in can share the load on new, trending or popular videos. Your browser, when playing a video, will fragment by fragment decide which server to get the content from, giving a smooth stream no matter what the load. The only extra requirement is that the original server is still online.

BTW, offloading storage and serving via cdn are also really easy in PeerTube, so you can go that route as well.