It’s a trust-minimized system but not completely trustless. I believe it would require something like 11 of the 15 block signers, which are companies/entities geographically spread across multiple continents/jurisdictions, to collude together. There’s nothing better and less risky than sats on-chain and in cold storage. But the risk with Liquid is less than holding sats in a custodial wallet like an exchange or a custodial lightning wallet.