C++ adds more high-level conveniences without actually removing the footguns and undefined behavior (much C code compiles in a C++ compiler).
Zig tries to keep the low-level C philosophy but have things more well factored and well defined. The result is you _can_ tinker in high-level code, yet "drop down" into low-level code as you desire.
(Compared to rust, you get fewer compiler-enforced guarantees, but unlike C the language isn't trying to make high-level code adversarial).