You don't need to write C or C++ when using a SQL RDMS, likewise .NET and Java shops don't need to write Go when using Docker/Kubernetes.
True, but I'm not talking about simple users. I'm talking about companies extending Kubernetes or building adjacent software. Even if their service doesn't necessarily integrate with Kubernetes, there is frequently a temptation to "follow your heroes".
Look at the whole Cloud Native Foundation thing, I think most of their projects are developed using Go.
So if you're using that stack, it's easy to assume that all new development everywhere is in Go.
It will probably balance out once the newness wears off Go (I think this is already happening).
Actually Rust in what concerns Microsoft.
https://deislabs.io/posts/still-rusting-one-year-later/
I should also note that after creating the initial support for Go on VSCode, they have given it away to Google to maintain it.
My anecdata kind of tells me that Go is reasonably big, but it's not yet near .NET and Java, worldwide. But it could get there in a few years, I've seen/heard about some enterprises adopting it.