When U.S. giants like Walmart or Amazon squeeze their suppliers, the natural consequence is cost-cutting and a drop in quality control. But for regional companies in Japan and Korea, regional mobility is incredibly difficult. In Japan, for instance, even politics is often "hereditary," and there is a strong overarching tendency for people and businesses to stay rooted in one specific region (while many do migrate to Tokyo, a vast number of people simply do not have that choice).
In the highly fluid U.S. corporate ecosystem, mobility is always an option. If a supplier loses a contract with Walmart, they can still pivot to another massive retailer, even if it's not quite as large.
Japan and Korea, however, have small landmasses, and the reputational risk is absolute. If a company's reputation is damaged by a single failure or a lost contract, their next job simply vanishes. Because of this existential threat, they fundamentally cannot compromise on quality. Imagine what happens to a small supplier in Japan if they are cut off by a mega-retailer like Aeon Mall. There is no backup giant waiting to take them. They are finished.
So, while geographical and structural differences dictate this extreme pursuit of quality, framing it as a "horizontal culture" is completely wrong. As an East Asian, I can confidently say that "horizontal culture" is the single most mismatched term you could possibly use to describe East Asia