To summarize the explanations i’ve come across: It’s tailored to Google’s internal teams maintaining tons of legacy C++ code, doesn’t cover exception handling, and generally has outdated advice best suited for the code they developed in that time period. While their style guide is ideal for maintaining consistency with Google’s existing codebase, someone working on a modern C++ project should consider using the language’s more modern features and STL components

Something I’d want to note though, someone developing in C++ for an embedded platform or even working on hardware drivers would probably have very lean and mean code which doesn’t conform to a particular style guide, especially ones advising against use of “unsafe” operations.