Most of the core products at Google are still written in pre-C++11.

I wish these services would be rewritten in Go!

That’s where a lot of the development time goes: trying to make incredibly small changes that cause cascading bugs and regressions a massive 2000s C++ codebase that doesn’t even use smart pointers half the time.

Also, I think the outside world has a very skewed view on Go and how development happens at Google. It’s still a rather bottom up, or at least distributed company. It’s hard to make hundreds of teams to actually do something. Most teams just ignored those top-down “write new code in Go” directives and continued using C++, Python, and Java.