Defer is a very simple feature where all code is still clearly visible and nothing is called behind your back. I write a lot of C++, and it's a vastly more complex language than "C with defer". Defer is so natural to C that all compilers have relatively broadly non-standard ways of mimicking it (e.g __attribute__((cleanup)).

If you want to write C++, write C++. If you want to write C, but want resource cleanup to be a bit nicer and more standard than __attribute__((cleanup)), use C with defer. The two are not comparable.