The spiritual struggle of the Israelites was rooted in deeply ingrained habits rather than sudden rebellion. The narrative of their actions is clear and speaks for itself, showing a simple truth about their internal condition [רד״ק].
As they strayed from God, their hearts were pulled toward false worship. This deep attraction was not a new temptation. Rather, they were drawn back to the familiar idols and foreign practices they had grown used to serving during their long years in Egypt [מצודת דוד].