Again, I couldn’t agree more. I think in the end what we will find is that the state needs to be sharded, so, in much the same way that we “shard and share” the Unchained Index via chunking and a manifest on IPFS, the state will be chunked, sharded, and shared on some sort of content-addressable store as well. (And, it can use the index to get to the right portion of the state.)
There’s a recent, related post about that here: Trustless access to Ethereum State with Swarm