As is true of many developers, I am part of a large team working inside an ecosystem of enormous C++ programs. These programs are written in a particular way (heavily templated) and built in a particular way (dynamic linkage, CMake) and it's neither feasible nor wise to change these foundations

I guess the point I am trying to make is if you had chosen to be statically-linked from the start, then it would be comparable to a Go binary of today. If Go had many dynamic dependencies and people became "stuck" with them, and Go later introduced statically-linked binaries, then it would be the same as your C/C++ example, wouldn't it? In other words, it's not a distinguishing factor because you can be fully statically-linked in C/C++ if starting today with a new project with that goal in mind.

Sure. But here we have a typical situation where the Go tools get it right by default, and of course a sophisticated engineer can achieve the same effect with non-Go tools even though those tools get it wrong by default