I'm not sure I like the "better C" label. After all, Zig allows you to easily do stuff that's virtually impossible in C, and only possible in C++ with templates and constexprs and concepts. It also doesn't have pointer arithmetic and pervasive wild casts, so it's not a "syntax-sugared Assembly". Its only similarity to C is that it is a low-level language and that, unlike other low-level languages that aren't C -- like C++, Rust, and Ada -- not only is it not among the most complex languages in the history of software (all three of those have probably secured their places in the top-five), but it is probably among the simplest.
> I'm not aware of any features that would amount to a "radical breakthrough". As far as I am aware, it is a modernized C, with nice compile time evaluation, async, and some runtime-provided safety guarantees. But nothing that is novel from a type system / language design point of view.
AFAIK, general partial evaluation with introspection as a single mechanism to do the work of generics, typeclasses/traits/concepts, value templates, macros, and conditional compilation -- combined with a general error reporting mechanism that is shared between runtime and compile-time -- has never been attempted before. It is revolutionary.