essentially our first communication is done with some central server
No, the first communication is made with your DNS server to fetch the key for encryption from an HTTPS record. If a record with key is found it is used to encrypt the Client Hello, otherwise it falls back to the unencrypted variant.
Cloudflare is not involved, unless you are hosting your domain through Cloudflare of course.
I am unfamiliar with QUIC, and quick search basically tells it is kinda like multilane highway for udp.
QUIC is primarily used for HTTP/3. The protocol was engineered and proposed by Google, same as with ECH and Cloudflare.
No, the first communication is made with your DNS server to fetch the key for encryption from an HTTPS record. If a record with key is found it is used to encrypt the Client Hello, otherwise it falls back to the unencrypted variant.
Cloudflare is not involved, unless you are hosting your domain through Cloudflare of course.
QUIC is primarily used for HTTP/3. The protocol was engineered and proposed by Google, same as with ECH and Cloudflare.