I am an economist and I am skeptical that the value will be large, remember that the planet has a 65 trillion dollar economy and so while a billion dollars is a lot of money to me, it isn't a lot of money in the big scheme of things.
On the surface, blockchain appears to improve accountability and reduce fraud. I said on the surface because very few large scale blockchain frauds have happened yet. Also, the most inefficient components of the world economy usually depend upon graft and those systems are resistant to implementing processes that improve accountability.
I do think that adding blockchain will improve system integrity, but I am wondering how the mafia will get to the outside nodes to degrade the information quality before it enters the process. Consider a WalMart buys a set of goods numbered X0001 through X0050 and they are physically delivered. Imagine that the shipping container is surreptitiously intercepted and a general manifest marking X0001 through X0050 as received goes through the process rather than the time consuming manual process of scanning each good. The blockchain is defeated.
Now let us imagine that the packaging for each good is given a RFID with a unique encryption. This is costly. The mafia hires hackers to break into the system from the source and determine the encryption system itself.
Learning from this, they hire amazing network security, so the mafia hires a janitor to bug the place and steal documents.
Blockchain is nothing more than a distributed information recording system. It is resistant to system destruction, facilitates verification and validation, and improves accountability but we have seen very few large scale failures. Consider this, the Internet is resistant to system destruction, facilitates verification and validation of actors and nearly guarantees signal propagation as long as enough underlying communication systems survive.
The Internet's value has been heavily located in porn and cat videos. Fraud is rampant and it is an open system, largely. So is blockchain. Open systems, like public highways, still depend upon policing and monitoring.
Although blockchain is proposing to replace centralized systems, as the Internet did for the postal service and BBS, it isn't clear that it will be of GREAT value for strong centralized systems. Instead, the gains will probably be in poor centralized systems such as the international wire system. It is aged, outmoded and outdated and hasn't seen real improvements in my lifetime. It hasn't changed greatly since its 19th-century antecedents. The same is true for the ACH system because Congress refuses to allocate the money. On the other hand, the Swedish or British systems are great.
My guess is that its greatest value will be in exposing graft. For example, if you could continuously track a container in a port in Ghana, then you could track what workers actually did what work and you would be able to expose clearly the pattern of bribes which speed up or slow down the harbor. That is, you could if the customs and dock workers use the tools as intended.
Blockchain just decentralizes signal. It is a human system and it will be implemented as part of greater human systems. I think roving bandits like hackers and stationary bandits like customs workers haven't had a real chance to attack it yet.
If I were working in blockchain, I would be working on the inputs to the system and not the system itself. The money is still in preventing GIGO.