You haven't used Windows in a while I imagine.

MSVC has stabilised the ABI since VS 2015, we are on VS 2026 now.

Due to customer pressure to stop doing exactly that, to the point some ISO C and C++ stuff that requires breaking the ABI has not been implemented thus far.

I am quite certain that I will find ABI breaks in GCC release notes since Slackware 2.0, when I used it for the first time.