> One of the biggest default security improvements with Web Crypto is that *cryption keys are _not readable by JS_ once instantiated - they can only be used by the cryptographic functions (unless you explicitly make them exportable). This is a subtle but very important defense against certain drive-by attacks that could dump loaded keys from whatever non-native JS crypto library you might be using.

That's a really nice feature. This should be better advertised. I wasn't aware that Web Crypto was even a thing.