If you are prepared to accept a lot of compromises in the name of stability then, as you say, C is right there! You have no reason to adopt Zig or anything else

If you are prepared to accept a lot of compromises in the name of stability then, as you say, C is right there! You have no reason to adopt Zig or anything else, C will outlive us all. If you're trying to offer something different than C, for people who aren't willing to accept those tradeoffs, then you have to do something different.