Everyone has been poor before; no one wants to return to the bitter days of the past. If sponsorships were cut off now, no one would live well. Obviously, there's another way to ensure everyone gets enough to eat—by reducing the number of "upper echelons" sharing the profits to a sufficiently low number.
Therefore, the problem isn't actually the merchants who control the powerful Knights, but rather the Knights themselves. These corrupt Knights fear not the merchants, but other Knights—their similarly corrupt comrades.
The nobles of the Irisflower People face the same problem.
The First Rebellion and the Second Rebellion were complete failures. In this world where extraordinary power is monopolized through knowledge, it is difficult for transcendent individuals to emerge among the purely impoverished commoners.
