There was already a better evolution of C called clay. It had templates and ownership. It was C compatible and could be used as a substitute.
https://github.com/jckarter/clay/wiki/Clay-for-C---programme...
https://github.com/jckarter/clay/wiki/Clay-for-C---programme...
Overloading is also generally missing from today's breed of C alternatives.
There has certainly been many attempts at C alternatives: eC, Cyclone etc etc