Cross-compilation is a big deal I'd say, I wouldn't brush it off as insignificant.
Even if I ignore cross-compilation, what other language has easy and fast native compilation, that produces relatively performant and low memory programs, is properly garbage collected, and has a good library ecosystem as well as a good concurrency story?
Other than good cross-compilation, I really don’t see any of that. Even niche languages that have been around forever hit this exact trio like D. Also, the performance is ain’t that good to begin with, for more complex scenarios the comparatively dumb GC of Go will be a bottleneck, compared to something like Java.