I'm gonna keep saying this forever - there are two obvious "killer apps" for crypto:

1. Semi-private blockchains, where you can rely on an actor not to be actively malicious, but still want to be able to cryptographically hold them to a past statement (think banks settling up with each other)

2. NFTs for tracking physical products through a logistics supply chain. Every time a container moves from one node to the next in a physical logistics chain (which includes tons of low trust "last mile" carriers), its corresponding NFT changes ownership as well. This could become as granular as there's money to support.

These would both provide material advantages above and beyond a centralized SQL database as there's no obvious central party that is trusted enough to operate that database. Neither has anything to do with retail investors or JPEGs though, so they'll never moon and you'll never hear about them.

AFAIK both of these use cases had many millions of invested dollars dumped into them during the Blockchain hype and neither resulted in anything. It might not be an exact match for (1), but there was famously the ASX blockchain project[0] which turned out to be a total failure. For (2), IBM made "Farmer Connect"[1], which is now almost entirely scrubbed from their website, which promised to do supply chain logistics on a blockchain.

[0] https://www.reuters.com/markets/australian-stock-exchanges-b...

[1] https://mediacenter.ibm.com/media/Farmer+Connect+%2B+IBM/1_8...

IMHO, most people misunderstand the real utility of crypto.

The thing to keep in mind is that replacing a database with computationally expensive crypto is sub-optimal. Supply Chain tracking falls into this category: why crypto over barcodes and a database?

Governments use Banks with their deterministic processes to manage and guarantee transactions. This is where crypto shines- replacing the entire banking system as an intermediary to manage and guarantee transactions. Crypto can do this better and cheaper than Banks.

There are other domains where the government is the backstop/guarantor and leverages intermediaries to manage the scale. Real Estate comes to mind. Identity is another. Crypto can be useful there.

One last useful crypto application is to replace governments themselves as the backstop and final/guarantor for transactions.

These are ideas that evoke strong reactions. There's a reason the inventor of crypto is anonymous, to this day.

The only "killer app" for crypto*currencies* is being a payment method. Not counting speculation. This is what they are used for right now, but the scale at which this happens doesn't justify their current valuation (even after recent losses).

Not only do you not need the blockchain for either of those things, you don't want it.

Think it through. How do you actually "cryptographically hold" someone to anything? You take them to court.

Guess what you can do, right now, without the blockchain? That's right, you can take them to court.

You're just reinventing normal contract law with extra steps.

The cryptographic part doesn't even help you when you can just say in court that "here are our records that show we gave them these packages, here are our records of customers filing complaints that they never got them" and that is completely fine.

All such private applications work better with a regular database.