There should be a language about as simple as c, with a few additional keywords for safety (type and memory), and a modern standard library -- that works basically everywhere C works, and is backwards compatible with C.
ie., we're missing --C++
I think all the supposed successors have approached the problem from the lang-design pov, where for C, it needs to be from-existing-compilers-and-tools pov.
I suspect there's a route to C v2 by starting with the C std, and gcc/clang, then working "forwards". Similar to cppfront for C++.
ie., it needs to compile 99% of all existing C code, it needs to compile to 90% of all in-use platform for C, etc.