The only way this becomes useful for comparing languages is if somebody gives evidence of correct implementations in other languages. You're claiming they exist but with no evidence and suggesting they're secret. How do you know those don't have bugs? Did any concurrency bug experts do extensive testing on them? And can we disprove secret Go implementations of the same quality?
No, they are citing that every Raft implementation that Antithesis has tested has bugs. The etcd implementation you note in go that has bugs also does tens of millions of QPS and is over a decade old. How are you confident that the proprietary implementations that presumably haven't been fully tested don't have subtle bugs that don't show up in practice?