Two reasons I can think of: 1. HTTP/2 was a 'new serialization' of the core HTTP data model. HTTP/3 is too, so since it was ratified it made sense to use HTTP/

Two reasons I can think of: 1. HTTP/2 was a 'new serialization' of the core HTTP data model. HTTP/3 is too, so since it was ratified it made sense to use HTTP/3 to keep things consistent. 2. QUIC still exists, but it's now the underlying framing/messaging protocol on top of UDP. I can imagine future internet protocols being developed on top of QUIC that don't need HTTP/3.