The long-term effects of the Black Death were huge; in fact, the Plague was one of the most significant events in human history. By most estimates, the plague killed around 60% of the ENTIRE population of Europe, and in just a few years.
The result of all this death was the Renaissance and, ultimately, the development of the modern world. Before the plague, most of Europe was feudal, meaning that aristocrats owned huge pieces of land, and serfs worked that land in exchange for being allowed to live on it. But the deaths of so many people meant that there were no longer enough serfs to sustain this system. The few workers who were left alive could now asked to be PAID for their work in money.
With so many people suddenly having cash in their pockets, markets started springing up to sell goods to these people. This basically meant that capitalism was born.
Another consequence was that there was a much greater need for technology to replace all the labor that was lost when so many people died. European technology advanced much more rapidly than it had before, and brought a lot of lifestyle changes with it. These lifestyle changes also shaped the way people thought about themselves and the world, which produced further changes in art, literature, culture, and religion.
TLDR: Tons of people died, resulting in capitalism, the Renaissance, and modernity.
