The people no longer obeying and worshiping Yahweh is spoken of as if they left Yahweh and went somewhere else. (See: [[rc://en/ta/man/jit/figs-metaphor]])
The people are speaking to Yahweh and refer to him as "our God." This can be stated in second person. Alternate translation: "abandoned you, our God" (See: [[rc://en/ta/man/jit/figs-123person]])