Let me try providing a different perspective based on experience. QUIC works amazingly well for _some_ kinds of machine to machine traffic.

ssh3, based on QUIC is quicker at dropping into a shell compared to ssh. The latency difference was clearly visible.

QUIC with the unreliable dgram extension is also a great way to implement port forwarding over ssh. Tunneling one reliable transport over another hides the packer losses in the upper layer.