QUIC does have more than just different congestion control For example it has forward error correction which can be very important for lossy connections. There

QUIC does have more than just different congestion control For example it has forward error correction which can be very important for lossy connections. There are other improvements that can't really be added to TCP either such as roaming between IP addresses. (MPTCP exists but IIUC requires make-before-break which is not always possible).