What are the most important reasons for the victory of the Netherlands in the fight against Spain?

There are the following main reasons for the victory of the Netherlands in the war with the Spanish Empire:

All segments of the population took part in the war;
The Netherlands supported other European states such as France, etc.
The cohesion of the population of the Netherlands, who opposed a common enemy.

Thus, in the middle of the 17th century, the Netherlands were able to achieve their independence. In addition, the territories captured during the war were annexed to the country.