C++ (and Java in a sense) are kind of a "local optimum" in terms of languages. Go breaks from that, an it's good. It's not necessarily faster (or slower), it's a different way of seeing things.

So C++ programmers think they need "all the speed" of C++ (ignoring all the cases where it's being slower because of the added complexity that C++ programs end up having) and convincing themselves that's the "only true way"

In some aspects that's true, you really shouldn't go for something outside of C/C++ in the embedded world usually (even though embedded systems are getting faster, but there are several specialist systems slower than your smartphone)

But for most apps today? Thanks, but I would try alternatives first.