Noting some of the sibling comments about timestamping and trust, something I've thought about before when explaining use of Blockchain is that the real use cas

Noting some of the sibling comments about timestamping and trust, something I've thought about before when explaining use of Blockchain is that the real use case is verifying the relative order and integrity of events. Clearly the time granularity within which you get relative order assurance will be dictated by the order interval. But where this seems to fall apart is if you need very precise ordering (think stock trades), as an unpermissioned chain won't going you a high enough block rate. So you move to a trusted node that mints blocks, and at this point you might as well call it a ledger computer, issuing signed receipts. The big unsolved problem is the analogue gap though, and how to get something from the real world into the chain - the person or device making the observation inherently need to become trusted oracles. In the odometer example, you could surely take a photo of the odometer before the joy ride, then submit the old picture once the vehicle is leaving your custody? Client side restrictions this is a live photo don't help as they can't be verified on-chain, so now the next person gets blamed? Or have I missed something here?