The Israelites had been able to avoid being totally destroyed because God wasn’t willing to give the surrounding nations (and their gods) anything to gloat over. Although, they had been warned.
But this time, the gloating had already started:
Jeremiah 33:24 Have you noticed what people are saying?—‘The Lord chose Judah and Israel and then abandoned them!’ They are sneering and saying that Israel is not worthy to be counted as a nation.
God had a different view: the gloating would stop when God stepped back in and restored Israels fortunes again:
Jeremiah 33:25-26 But this is what the Lord says: I would no more reject my people than I would change my laws that govern night and day, earth and sky. I will never abandon the descendants of Jacob or David, my servant, or change the plan that David’s descendants will rule the descendants of Abraham, Isaac, and Jacob. Instead, I will restore them to their land and have mercy on them.