Flawed analogy. Lightning isn't a federated sidechain. While operating decentrally, Liquid isn't permissionless in the same way Lightning is. Summarily, Liquid acts as a financial instrument between large Bitcoin companies, which are integral to its operation. It is trust requiring, but it minimizes it, because it divides governance to several trustworthy entities.

Lightning, on the other hand, requires no faith. You need to trust nobody but yourself to transact. Not your partners, not your partners' partners, no one.