It is. The bare API of QUIC would now mostly look just like TCP/IP streams. You have bidirectional byte streams with flow-control. The main difference from an

It is. The bare API of QUIC would now mostly look just like TCP/IP streams. You have bidirectional byte streams with flow-control. The main difference from an API pointer of view is that there is an additional multiplexing layer. On TCP/IP the byte stream is directly on the connection. On QUIC a connection can contain multiple streams - which are openable by both sides. And each of those streams is a bidirectional or unidirectional byte streams. QUIC doesn't care what protocol you run on top of those streams. HTTP/3 is just the only one which is specified at the moment.