The only VPN technology I see that blends as HTTPS is MASQUE IP Proxying, and the only implementation I know that does this is iCloud Private Relay. It is also trivial to block because blocking 443/udp doesn't really affect accessing the Internet.

Cloudflare WARP (1.1.1.1 tunnel or Zero Trust) run by default on MASQUE

Ah that's true, they originally started off with a rust implementation of Wireguard but have since moved to MASQUE.

Not the only, AFAIK Shadowsocks with xray-core can pretend to be a 443/tcp HTTPS server.

Thanks for this, really couldn't find any English explanation of xray-core though.