Isn't zig more or less the closest thing we have for this currently? I really ask naively, without proper insights to give a relevant answer myself.

Some would say that would be Zig, although it is more like Modula-2 safety guarantees.

So...C#? Structs + managed references and spans instead of raw pointers for memory ranges.

I think most gamedevs will reamain in higher level languages. Gone are the days when game developers were wizards of esoteric programming knowledge and elite skill; most game developers I've met are creative types who came to programming as a tool for expressing themselves, and not programmers who use their obscure knowledge to make creative things. Artists, not engineers.

For people who want to use programming as a tool for expressing themselves, C#, python, and, above all, visual programming are going to remain the most popular choices. They don't care about memory management or type theory, they just want to easily describe the behavior of things in a language which more closely mimics human thought