US and Chinese Companies Train Almost All of the Most-Used AI Models

An Our World in Data article argues that companies in the United States and China train almost all of the world’s most-used AI models. The claim highlights concentration in both frontier-model development and practical adoption. However, the supplied Hacker News metadata does not include the underlying model list, percentages, time window, or methodology, so the strength and scope of the conclusion require checking the original article and its data sources.