That has been around for years:

https://github.com/moul/quicssh

I guess it didn't get traction… whether that happens honestly feels like a fickle, random thing.

To be fair, a go project as sole implementation (I assume it is that?) is a no-go, for example we couldn't even deploy it on all our systems since last I checked Go doesn't support ppc64. (BE, not ppc64le)

I also don't see a protocol specification in there.

[edit] actually, no, this is not SSH over QUIC. This is SSH over single bidi stream transport over QUIC, it's just a ProxyCommand. That's not how SSH over QUIC should behave, it needs to be natively QUIC so it can take advantage of the multi-stream features. And the built-in TLS.