As someone who programmed COM back in the day for C++ applications, I can tell you definitively that you got no benefits over other languages outside of brittle

As someone who programmed COM back in the day for C++ applications, I can tell you definitively that you got no benefits over other languages outside of brittle macros and non-standardized Visual C++ compiler magics. Especially once you crossed over into Office/VB land, and everything was just IDispatch, Variants, BSTRs and SafeArrays.