This is from some 10 years of Go experience. But like you say, it is not really about Go; my point is about the illusion of productivity that familiarity brings; it is very deceptive and hurts productivity in the long term.
Need to write, say, a network service? Go can no doubt give just about anything else a productivity run for their money. Need to solve a machine learning problem? ... Good luck. It can be done, of course, but you're quite likely in for a whole lot of extra work not needed in other ecosystems, destroying any semblance of productivity.
In other words, the comment is a thinly veiled "use the right tool for the job".
If you're familiar with a tool, you might be able to "get something" a lot quicker with it than learn to use the correct tool, but on the long term, the correct tool pays off better.
But what I do 95% of the time is backend services with APIs and CLI tooling, for both it's amazing.
For GUIs it's hit and miss. There are some attempts at tooling, but they all feel a bit off to me. But Rust the same issue, as does C#.
We need a modern Visual Basic again =)