Question

Why was mercantilism used by so many countries

Answer 1

governments used their economies to augment state power at the expense of other countries.
Governments sought to ensure that exports exceeded imports and to accumulate wealth

Answer 2

Mercantilism is an economic practice by which governments used their economies to augment state power at the expense of other countries. Governments sought to ensure that exports exceeded imports and to accumulate wealth in the form of bullion (mostly gold and silver).

Hopefully this helps!!