The Dutch fought and won several wars against the English, fought for independence against the Spanish, established a large colonial empire and became a dominant naval and power and hub of freedom of religion and speech in the 17th century, at least, that's what I've been taught.
In the 19th century, little of that was left over, the Netherlands lost most of that, and the balance of power had shifted towards England becoming the largest empire in the world. While referring to it as a "downfall" may be a bit much, there really seems to be a shift of power away from the country. What was the reason for this big shift?
I apologize for any historical errors in this post; my history education was long ago and wasn't exactly top-notch either.
Great question!
To give a meaningful answer, I will focus my post on the VOC, the Dutch East India Company, whose rise and decline are significant factors in the rise and decline of the Dutch Empire.
Let us consider three factors that allowed the VOC to become the world's largest global company: 1) Capitalistic investment via shares and dividents, 2) Trade between Asia and Europe, and 3) Trade between Asian countries.
The last one is often overlooked. For a very long time the VOC had exclusive rights to trade with Japan, and had holdings in Persia, South Asia, Southeast Asia, East Asia. In the 17th century they developed a sophisticated network of trade: Cotton and opium from India were sold in China. The money was used to buy porcelain and tea, sold in Japan. Here, they also sold European firearms and Indian tea along with Chinese tea. The Japanese paid them in silver and minerals. These were then used to buy spices in Indonesia. Eventually some of these things were also consolidated in Batavia (today's Jakarta) to be shipped back to Europe.
This lasted for a while, until the second part of the 17th century when the Anglo-Dutch Wars commenced. Due to this, shipments between Europe and Asia became difficult. Price of spices spiked, giving the English incentive to try to expand their own influence in Asia.
The intra-Asia trade also suffered for a variety of reasons, including growing rivalry between China's Ming Dynasty and the VOC. The Ming rulers supported local powers to usurp Dutch control in Taiwan, severing their trade with Japan. For a while the Dutch tried to encourage the Japanese to develop their own porcelain, to mixed success.
In Batavia, the situation also wasn't all rosy. The practice of sending all Asian goods to Batavia for consolidation and control, became problematic with growing corruption, and the English controlling Bengkulu in Sumatra in the early 1700s. The fourth and last Anglo-Dutch war (1780-1784) was extremely bad for the Dutch, as the Cape Colony at the tip of South Africa was threatened, Ceylon and Indian colonies were lost, and they had to trade Malacca for Bengkulu.
Finally, the VOC itself shot itself in the foot by over-paying dividends even when profits shrank, and had to declare bankruptcy in 1798. Just in time for the French Revolution to break out, and the French establishment of the Batavian Republic.