WBTC is one entity, Liquid is a contractual consensus of financially unrelated entities who would need to block you by majority. Also, lightning payments backed by Liquid channels don't go on chain, so they don't have much say about payments (this is very different to for example wallet of Satoshi, they can do lightning payment level censorship, Liquid not so much).

Also, since it's one Lightning network, you can get out through independently operated bridge, not through their multisig.

Yes, it's not Bitcoin mainnet, but it has pretty good balance of fees vs privacy vs distribution of decisions for many smaller channels that would otherwise not be possible.