Among those born of women, no one was greater than John the Baptizer, in the sense that to John alone was given the privilege of publicly introducing the Redeemer. Even our Lady did not enjoy this blessing! John was thus the greatest prophet, and the greatest party to the Old Covenant, the purpose of which was to foreshadow the Messiah.
The New Covenant began with Mary and Jesus. And so, the least member of the Catholic Church, the Kingdom of God begun on earth, is greater than John. The least among Catholics - incorporated into Christ Himself through Baptism, nourished with His own Body and Blood - is greater than the greatest figures of the Old Testament, indeed greater (more blessed) than all of them put together.
Wow.