Bounds safety by default, nullability is opt-in and checks are enforced by the type-system, far less "undefined behaviour", less implicit integer casting (the ergonomics could still use some work here), etc.
This is on top of the cultural part, which has led to idiomatic Zig being less likely to heap allocate in the first place, and more likely to consider ownership in advance. This part shouldn't be underestimated.
You presumably intend "shouldn't be underestimated" rather than "can't be". I agree that culture is crucial, but the technology needs to support that culture and in this respect Zig's technology is lacking. I would love to imagine that the culture drives technology such that Zig will fix the problem before 1.0, but Zig is very much an auteur language like Jai or Odin, Andrew decides and he does not seem to have quite the same outlook so I do not expect that.
This is on top of the cultural part, which has led to idiomatic Zig being less likely to heap allocate in the first place, and more likely to consider ownership in advance. This part shouldn't be underestimated.