Although the crusades failed, they had a major impact on Western Europe.
The crusades helped to break down feudalism by increasing the authority of kings:
Some nobles died in battle without leaving an heir. Their lands passed to the king.
Some nobles sold their land to raise money to pay the special tax levied by the king to offset the cost of the crusades.
Some nobles gave their serfs a chance to buy their freedom in an effort to raise the monies they needed to buy armor and weapons. Those young men who could buy their way out joined the crusades. Many died. That reduced the work force. Without workers, farms failed. If a farm failed, it would pass to the king.
Peasants: Many young men joined the crusades for adventure. If a peasant died, while serving in the crusades, the king got his land as well.
With all this influx of land and money paid to them, the kings grew to have great power.
From their explosure to superior Muslim technology, Europeans learned many new things including different ways to build and sail ships and how to make and use magnetic compasses. Europeans were also introduced to many new trade goods while on crusade, including silk, cotton, different spices, and new forms of art and literature.
The impact on Europe was tremendous. It increased the desire for trade with other parts of the world. This lead to the rise of the merchant class, the end of serfdom, and the beginning of the end of feudalism.