Black death didn't kill feudalism ( even if we could come to a consensus on what feudalism is ). The societal structure wasn't affected by the black death. Feudalism died as european monarchs and elites got wealthy and used that wealth to centralize power. Feudalism is a result of weak or nonexistent central power. A classic example of this is japan during the meiji period. The emperor centralized power by overthrowing the feudal lords of japan. Which he was able to because he opened trade and gained investment and weapons from the west which gave him enough power to central japan's feudal estates under his direct rule.

The black death didn't cause rises in wages. What caused wages to rises was trade. There as something called the mongol empire ( you might have heard of it ) which allowed europe to trade directly with china, india and the rest of asia. The mongol empire ( particularly the golden horde ) was central to european wealth generation. So much so that when it finally fell in 1480, wealthy merchants were desperately seeking another trade route to the east. A few years later, you have columbus ( you might have heard of him as well ).

The idea that death caused wage rises is ludicrous when you think about it for a second. If population decline causes wage increases then japan would be seeing a huge rise in income. Russia in the 90s should have seen a ridiculous rise in income.

What increases wages are increasing population and increasing trade.