After ~2 years of development, the TLS feature is finally in an usable state where clients can connect to popular sites and servers can negotiate basic handshakes.
On its own the RFC-8446 specification is huge, complex and prone to errors, not to mention other associated features like ECH or DTLS. That is why features like PSK, HRR and 0-RTT are still not supported but they will probably be added in the future.