sleeping giant

a person, organization, or entity that has immense potential, power, or influence, but is currently inactive, unaware, or not utilizing their capabilities

It is likely that the origin of "sleeping giant" comes from a quote attributed to Napoleon Bonaparte, who allegedly said, "China is a sleeping giant. Let her sleep, for when she wakes she will move the world." This quote suggests that China had great potential as a world power but had not yet fully realized its power. The idiom "sleeping giant" is commonly used to describe a person, group, or organization that has great potential or power but has not yet been fully utilized or realized.