> Why hasn't public key cryptography taken off as a sign in solution in the same way that email or Google or Facebook have been?
Because people haven't been financially motivated to evangelize it.
I believe that's the core of blockchain/web3 innovations. It's a worse way to do it, but the social hype (driven almost entirely by get rich FOMO) is enough to push it over the edge.
The most efficient way to do it would be to bootstrap the ecosystem with blockchain buzziness and then just deprecate the blockchain part eventually. MetaMask already relies on "Web2" apis to query blockchains, who says they have to actually hit a blockchain all the time?
A user’s transaction on Coinbase rarely represents an actual transaction on the blockchain. A transaction actually represents a row in a Coinbase SQL database, which Coinbase will eventually batch and then convert into a blockchain operation.
Coinbase is a centralized exchange. Of course it runs in a SQL db or whatever. They only need to touch the chain when settling inflows/outflows.
But something like Uniswap: https://app.uniswap.org/#/swap is fully on-chain. Every trade happens on chain, because the application is an immutable smart contract liquidity protocol, called an AMM, or automated market maker.
> MetaMask already relies on "Web2" apis to query blockchains
False. MetaMask uses Infura as a default, but you can edit your RPC URL to whatever you want. You can even run your own node and sync the chain if you've got a couple hundred gigabytes to spare (no stake required to run a non-validating node).
They don't have to hit the blockchain all the time. Only when it makes sense. For everything else, there's off-chain signatures. That's the beauty of it. Hey, you don't want to use the chain, just use the sign-in with Ethereum feature, and that's totally cool!
Because people haven't been financially motivated to evangelize it.
I believe that's the core of blockchain/web3 innovations. It's a worse way to do it, but the social hype (driven almost entirely by get rich FOMO) is enough to push it over the edge.