This is true, though it’s worth mentioning that 0-RTT on TLS 1.3 + HTTP/2 still has one more roundtrip (for the TCP connection) than 0-RTT HTTP/3. Plus even if

This is true, though it’s worth mentioning that 0-RTT on TLS 1.3 + HTTP/2 still has one more roundtrip (for the TCP connection) than 0-RTT HTTP/3. Plus even if you don’t enable 0-RTT on either there’s still a one roundtrip difference in favor of HTTP/3, since it combines the (equivalent of) the TCP establishment roundtrip and the TLS handshake roundtrip. That’s the real advantage in connection establishment.