The general thought is that blockchain technology will make the system honest but things are further from the truth. Yes there is transparency on the blockchain because the transaction are there for all to see. However, before it is on the blockchain it need to go on the blockchain and this is when honesty comes into play. I may not have the physical and still sell you a piece and then I put it on the blockchain. You have never seen the physical so you just believe it is there because it is on the blockchain. So you need to be careful who you trust with physical.