Banks are not known for using the best/safest solutions. Just take 4 digit pins and 3DES into account for example.
> who only offer certs of RSA and P-{256,384}?
I am pretty sure that nginx and openssl only recently added support for ed25519 certificates. Although to be honest I don't really like the idea of let's encrypt. The addressing system that tor uses has solved that issue already.
> but where most browsers use secp256r1?
This is an issue. Browser vendors should prioritize the djb algorithms.
> who only offer certs of RSA and P-{256,384}?
I am pretty sure that nginx and openssl only recently added support for ed25519 certificates. Although to be honest I don't really like the idea of let's encrypt. The addressing system that tor uses has solved that issue already.
> but where most browsers use secp256r1?
This is an issue. Browser vendors should prioritize the djb algorithms.