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”
I’m going to give you the benefit of the doubt and assume what you said was simply confusing, but not wrong.
So just to be clear if your raid array fails, and you’re using software raid, you can plug all of the disks into a new machine and use it there. But you can’t just take a single disk out of a raid 5 array, for example, and plug it in and use it as a normal USB hard drive that just had some of the files on it, or something. Even if you built the array using soft-raid.