Language-specific conferences are not just a C++ thing, though. There are Java conferences, Ruby conferences, Python conferences, Rust conferences, etc.
The only thing that doesn't exist is a C conference, but that's because C is the least common denominator.
Pretty sure that there are Go conferences.
There are. GopherCons are a thing. Also, here's an ad for the upcoming GopherConAU : https://gophercon.com.au.
CFPs are open until end of June. https://papercall.io/gophercon-au-2019
I've used C (closer to Go than Rust) and I've used C++ (closer to Rust than Go) in previous jobs. My experience is that the C programmers tend to focus on the problem at hand. On C++ teams, people spend a lot of time going to C++ conferences and discussing the idiomatic approach to mundane tasks in their superior language. I imagine we'll see the same thing happen in Go and Rust... different personalities are drawn to the different languages.
I'd rather be going to security, networking and crypto conferences instead of wasting a lot of time on a particular language.