The blockchain has nothing to say about trust outside of its ledger, which is to say in the physical world. Even if you try and hook it up to physical sensors, the sensors themselves can be compromised just like anything else. Any people who are currently distrusted by other people could just as easily put lies into the blockchain, so it has nothing to say about that kind of trust either. The only thing the blockchain allows you to trust is “X was entered into the blockchain previously”.