Knowing the folks at IA I’m sure they would love a backup. They would love a community. I’m sure they don’t want to be the only ones doing this. But dang, they’ve got like 99 Petabytes of data. I don’t know about you, but my NAS doesn’t have that laying around…
You should look up IPFS! It’s trying to be kinda like that.
It’ll always be slower than a CDN, though, partly because CDNs pay big money to be that fast, but also anything p2p is always going to have some overhead while the swarm tries to find something. It’s just a more complicated problem that necessarily has more layers.
But that doesn’t mean it’s not possible for it to be “fast enough”