I do like D. I've written a game in it and enjoyed it a lot. I would encourage others to check it out.
But it's not a C replacement. BetterC feels like an afterthought. A nice bonus. Not a primary focus. E.g. the language is designed to use exceptions for error handling, so of course there's no feature for BetterC dedicated to error handling.
Being a better C is the one and only focus of Zig. So it has features for doing error handling without exceptions.
D is not going to replace C, perhaps for the same reasons subsets of C++ didn't.
I don't know if Zig and Rust will. But there's a better chance since they actually bring a lot of stuff to the table that arguably make them better at being a C-like language than C. I am really hyped to see how embedded development will be in Zig after the new IO interface lands.