Backwards compatibility for code is important, like progress in language evolution. I have question regarding "C has no ABI that could be affected by this, C do

Backwards compatibility for code is important, like progress in language evolution. I have question regarding "C has no ABI that could be affected by this, C doesn’t even respect qualifiers, how are we breaking things?!" We have language standards for changes like this like '-std=c2x' or '-std=c89' with GNU's GCC. I understand and accept the matter of avoiding breakage. Furthermore C is inherently weakly typed, contrary to C++ which is strongly typed. Something you probably should not change, because that are basic language features. But the option to set the language standard does exist for this situation, to allow changes which will affect users. So why it cannot be used here? That is not a critic. I'm sure that have their rationale for that and know more than me. PS: Some changes will break the ABI, in that cases we likely see a PREPROCESSOR variable or something like that which is more complicated. The GCC people used it for some changes to std::string if I remember correctly.