I understand that most people don't use it and indeed rely on tofu, but the statement is not absolutely correct.

ssh server keys can be authenticated using (the DNSSEC "CA" system and) SSHFP, and it's possible to setup a signing CA for the host key (similar to ssh certificates, however not applicable for foreign servers). And of course, the fingerprint could be advertised out of band e.g. on the homepage with tls