Thats all true, but do note that the rewards get better every time your league gets harder to reach. The lack of loot from the rewards are because the game encourages you to fight other people for it as this is the main focus of the game. If you reach silver, you can earn stronghold troops as rewards to help you fight battles. The rewards are here to show how well you have done in the game and not to scam you or whatsoever. If you still think that the rewards from leagues are not good, my final message is: at least it is better than having no rewards from joining leagues.
I'm cakeden of conqueror quest and i'm happy to help.