Google developed Go specifically so they didn't have to use C++ in high-volume web backends, which is what they did previously.

These aren't high-volume, they're just web interfaces used internally by hundreds of people. Golang wasn't well-received either.

Another (maybe even more) important motivation was to have simple, statically-typed language so that new hires can contribute to the codebase faster and the code itself is more standardized and easier to maintain at large scale.

They basically got there with Java + some frameworks. It's not the best, but it works and has a huge ecosystem already. Some people complain that Golang is designed specifically for its original use case of specialized web backends and isn't great otherwise, or that its main design goal was being "not C++."

Yeah, it matters to have something new hires can use, which is one of the big flaws in not caring about the outside world. Our team lost three people recently because they took the job expecting low-to-mid level C++ type work and instead got this web stuff and got bored. It's either that or they get web people who struggle not to create segfaults.

Google absolutely uses lots of C++ in high-volume web backends today. Go didn't replace it.

A few people at Google did, as far as I'm aware it didn't start as some officially sanctioned project at the company. golang has its own sets of challenges due to the limitations of the language and its error prone bare bones threading model.

Nope, Google is fine with Java and C++.

Go authors always disliked C++, and got a manager that allowed them to work on their toy language, which eventually became Go.