We’re living post-Millennial Kingdom (the little season of Revelation 20:7)

Futurist dispensationalism teaches that the Lord delayed His return indefinitely, whereas scripture tells us that the Lord would return within a generation to judge apostate Jerusalem (Mystery Babylon) and set up His Millennial Kingdom. So, this means we are living in the little season of Revelation 20:7 that follows the Millennial Kingdom. Why doesn’t the modern-day church system teach on this age of deception that comes after the thousand years of peace and prosperity?