Unix creators called Unix "dead and rotten" because the eulogy was done by Perl, and Plan9/9front and Inferno obliterated it. Ditto with C+POSIX against Plan9's C (and 9front) and Inferno vs Limbo, the grandparents of Golang, which is seen from Pike and so as the tool set C++ should have been.
Golang it's like Windows NT. C++ it's like Windows ME, it might have their cases on RT performance and multimedia because of having far less layers than NT, (and much better on single core), but it crumbles down fast and it was really easy to shoot yourself in the foot. Windows 2000 and XP killed it for the good.
Some day Golang would be performant enough (even with CSP) with multiple cores so all the 'performance' advanteges -suppossedly C++ brings- aren't needed at all.
Even C# can be as good as C++ today in tons of cases (AOT and emulators like Ryuyinx are not a bluff), even SBCL for Common Lisp too if you finetune the compiling options.