As of TLS 1.3, the ClientHello (which includes the Server Name Identification (SNI) extension) is still sent in plaintext. There is a current draft for encrypted client hellos[0], but I don't think its adoption is widespread. QUIC appears to encrypt the ClientHello; however, it does not protect from an attacker which can observe the initial connection packets[1].

[0]: https://datatracker.ietf.org/doc/draft-ietf-tls-esni/

[1]: https://www.rfc-editor.org/rfc/rfc9001.html#name-security-of...