Unlike DeepSeek’s previous blockbuster, which performed as well as the best Western models but for a fraction of the cost, v4 was not cheap to build https://www.economist.com/business/2026/04/28/why-deepseeks-sequel-failed-to-impress?taid=69f53e8f083ff200013abd7e&utm_campaign=trueanthem&utm_medium=social&utm_source=twitter