Ideally it stops at the point where the tools actually affect your project.
Does everyone need to use the same IDE? Obviously not. Same C++ compiler? Ideally yes. (And yes you can do that in some cases, e.g. Bazel and its ilk allow you to vendor compilers.)
Does everyone need to use the same IDE? Obviously not. Same C++ compiler? Ideally yes. (And yes you can do that in some cases, e.g. Bazel and its ilk allow you to vendor compilers.)