The multi-chain future is likely one that encompasses the idea of sovereign “clusters” of blockchains that can bridge to each other in a trust-minimized way.
Trust-minimized bridging is facilitated by the chains sharing security with a common data layer like Celestia. twitter.com/VitalikButerin/status/1479501366192132099
An example of this is a rollup and its parent chain. With trust-minimized bridging funds can’t be stolen directly from the bridge.
This is the opposite for bridging between clusters where funds can be stolen by the committee that operates the bridge, like the ETH-Polygon bridge.
How does Celestia fit in a multi-chain future?
It provides the core piece for building clusters of chains, a modular data availability and shared security layer.
Sovereign clusters of chains can easily bootstrap and deploy on Celestia to utilize its scalable data availability.
Celestia itself is not a cluster of chains because it doesn't provide a smart contract environment, but rather multiple clusters of chains can exist *on top of Celestia*, by using Celestia as the base data availability and consensus layer.
They will also be able to conduct trust-minimized bridging with other chains in the same cluster on Celestia because they will inherit the security of Celestia’s validators.