Answer:

We're no longer in the last days of the Old Covenant age. Those "last days" referred to the final generation of Israel under the Law, leading up to its judgment and destruction in 70 AD. That's why Peter could confidently say, "This is what was spoken of through the prophet Joel... in the last days" (Acts 2:16-17), and why the writer of Hebrews said God "has spoken to us in His Son in these last days" (Hebrews 1:2).

Now we're living in the age that followed, the everlasting New Covenant age, the kingdom that cannot be shaken (Hebrews 12:28). The old world passed away, and we're in what the prophets longed to see: the fulfilled reign of Christ, not waiting for the end, but living in what came after it.