it’s… curl, it’s supposed to do all the networking protocol things

Anything that involves high latency and/or packet loss. And in general: testing servers.

The question is also a bit odd, to be honest. There's no need to look for a beneficial use case to add support for the next iteration of the HTTP protocol.

It will be able to speak http3.

Testing your http/3 endpoint

So what were the dangers with QUIC protocol again? That the big-tech would control the market?

No