In particular, it has two truly remarkable features that no other well-known low-level language -- C, C++, Ada, and Rust -- have or can ever have: lack of macros and lack of generics (and the associated concepts/typeclasses) [1]. These are very important features because they have a big impact on language complexity. Despite these features, Zig can do virtually everything those languages do with macros [2] and/or generics (including concepts/typeclasses), and with the same level of compile-time type safety and performance: their uses become natural applications of Zig's "superfeature" -- comptime.
Other languages -- like Nim, D, C++ and Rust also have a feature similar to Zig's comptime or are gradually getting there -- but what Zig noticed was that this simple feature makes several other complex and/or potentially harmful features redundant. Antoine de Saint-Exupery said that "perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away." I think that Zig, like Scheme -- and yes, there are others -- is close to that minimalist vision of perfection.
What a truly inspiring language. Rather than asking how we could make C++'s general philosophy work better as another increasingly famous language does, IMO, it asks how we could reshape low-level programming in a way that's a more radical break with the past. I think it's a better question to ask. Now all there's left to hope for is that Zig gets to 1.0 and gains some traction. I, for one, would love to find a suitable alternative to C++, and I believe Zig is the first language that could achieve that in a way that suits my particular taste.
[1]: I guess C has the second feature, but it loses both expressivity and performance because of it.
[2]: Without the less desirable things people can do with macros.