To understand this place is to understand the medieval mind.
The society in which we find ourselves is one of the very few that do not mark the transition between boy and man. By coincidence (or maybe not) western societies also have the longest and most traumatic period of semi adulthood. of any society I know of.
The City.. as in most things does it differently.
The City has always viewed manhood in economic terms. When a boy has learned a trade and can maintain his own business and support a family then he is a man. This transition takes place when he is awarded Freeman status, often in this church.
Male initiation is never easy, but societies that manage the process can make it quick. The aboriginal proves his independence by doing his walkabout where he travels alone for many months a a nomad eating only what he can find and kill. If he becomes sick or is injured he may not survive the ordeal. As I say, initiation is never easy.
The city required that a man become competent and responsible in business. He must work for many years under a master to achieve this but once he has been initiated into Freeman-ship he is the equal of any other man- an astonishingly progressive thing for the 14th century.
In the modern age the hard medieval apprenticeship has been replaced with charitable work of various kinds but the principle remains the same. Freeman-ship is earned- and valued all the more as a result.