As of OpenSSH 9.5 the default has changed, so you don't have to specify anything:
* ssh-keygen(1): generate Ed25519 keys by default. Ed25519 public keys
are very convenient due to their small size. Ed25519 keys are
specified in RFC 8709 and OpenSSH has supported them since version 6.5
(January 2014).
As of OpenSSH 9.5 the default has changed, so you don't have to specify anything:
* https://www.openssh.com/txt/release-9.5