Thank you for the interpretative question on Luke 7:28, “What did Jesus mean at Lk 7:28)?”
As I thought about your question, one may want to consider looking at various passages regarding the life of John the Baptist as in John 1. Matthew 3 and Luke 3. The reason is that Jesus is commenting on John the Baptist’s life. By reading his words, one may be able to see/perceive the reason for Jesus’ statement.
Here is the broader context of Luke 7:28:
“After John’s messengers left, Jesus began to speak to the crowd about John: “What did you go out into the wilderness to see? A reed swayed by the wind? 25 If not, what did you go out to see? A man dressed in fine clothes? No, those who wear expensive clothes and indulge in luxury are in palaces. 26 But what did you go out to see? A prophet? Yes, I tell you, and more than a prophet. 27 This is the one about whom it is written: “‘I will send my messenger ahead of you, who will prepare your way before you.’[b] 28 I tell you, among those born of women there is no one greater than John; yet the one who is least in the kingdom of God is greater than he.”
Here are some thoughts for one’s consideration about Jesus statement on Luke 7:28:
A. John the Baptist is greater than any previous person or prophet for he announced the coming of the Messiah. The other prophets prophesized about the Messiah’s coming, but he was the forerunner of the Messiah (John 1:23).
B. John the Baptist is greater than any previous person or prophet for he pointed out the Messiah. The other prophets only described the Messiah (John 1:31).
C. John the Baptist is greater than any previous person or prophet for he brought national revival to Israel. The other prophets hope for revival/repentance by Israel but rarely seen it happened.
D. John the Baptist is greater than any previous person or prophet for his humility and submission to God that the Messiah must increase and that he must decreased (John 3:30).
E. John the Baptist is greater than any previous person or prophet for he didn’t insist on his rights as the forerunner of the Messiah. Rightfully as the forerunner, he could have had all the pomp of association with the Messiah. He didn’t dress in royal robe as one would have expected. His clothing was less than the average person (Luke 7:24–25).
Thus for one’s consideration, he is greater than any other person because of his position and privilege of being THE forerunner and yet never insisting on his rights as the forerunner.
On the flip side, a person is greater than John not in terms of position or status for there will be many who will serve the Lord in unnoticed places to God. She/he may not have the recognized fame of John before the Jewish people. The children’s workers or the youth workers, those serving in positions that few would desire to accept will be recognized by the Lord. The Lord will highly commend those individuals for their service to him on earth. The Lord will commend each person for their faithfulness even as John the Baptists ran his race faithfully and humbly before God.
SUMMARY: Greatness is not based on position or power on earth but on faithfulness and humility, doing whatever God calls that person to do. God will exalt that servant of his and his deeds before the Bema Seat of Christ (I Cor. 3:10–14).
For additional perspectives:
https://thechristiancorner.quora.com/What-did-Jesus-mean-at-LK-7-28