- creating a secure timestamped append only log of signed messages
- apps like multisig wallets, privacy preserving rollups, cross-site attestations
- creating a global namespace registry for social networks[1]
- building other things on top of these primitives, like disintermediated collectibles for games, art, web communities..
[1] https://www.varunsrinivasan.com/2022/01/11/sufficient-decent...
For example multisigs, without crypto, require a trusted and centralized custodian, and if you are lucky you might get a permissioned API that exposes a few end points that were dreamed up by engineers at Stripe or some new tech-startup digital bank.
The closest example might be to point to TCP/IP which makes up the web and is (pretty) decentralized. Companies and even monopolies compete on top of this protocol but no single company wholly owns it. Although, ensuring decentralization tends to be a much more strongly considered goal in blockchains than what we’ve seen on the internet.
It’s a long read but “The Crypto Story” does a pretty great job at distilling some of the motivations: