From what I understand, the Liquid sidechain is a permissioned network where node operators essentially sign blocks. A block is considered final once 2/3rd of the nodes have signed a block. It is a pretty straight forward majority based consensus algorithm, with no byzantine fault tolerance because you trust the nodes.
And since you trust nodes (which I think will largely be exchanges and financial institutions) they will be pretty obedient of the state, unless of course they chose to do whatever they do, fuck things up and then ask for a bail out. But I digress.
I think Liquid and other sidechains (if any follow) will make bitcoin more accessible to financial institutions, so in all this is great stuff, if you want that. But once you peg your bitcoin off the bitcoin blockchain into a sidechain, you are completely in state/fintech land.