When it comes to 4096 the only viable benefit seems to be the key size and performance. While I certainly agree with that and I wish I could use ed25519, I can't use it with my security keys.

Yubikey currently supports 4096 bit RSA keys as a part of GPG applet. There's a PIV module, however in terms of elliptic curves it only has ec256 and ec384 and I still can't get ssh and pkcs11 to pick up anything other than built-in 2048 RSA keys.