throughout history, the wealthy and powerful tend to create a set of rules for themselves to follow- european gentry, for example, developed specific rules for speech, dress, eating, manners, etc etc. and to some extent these rules did restrain them, but at the same time, it gave them power- by following these rules, you show your status as someone with power, both to other powerful people, and to those of lower class. certainly there were nobles who chafed under these rules, but the vast majority of them, consciously or subconsciously, accept them as the price for power, even enjoyed performing them as a status symbol. it would be ridiculous to say that the nobility was oppressed by feudialism- they wielded incredible power and freedom to use that power to hurt others, even if they had to play by a handful of rules to do so.