The export controls made it difficult for Chinese companies to acquire large numbers of GPUs, which prevented them from expanding business models that rely on buying more GPUs to serve more customers, which means that Chinese companies have much, much lower budgets for GPU procurement than their American counterparts. https://chinai.substack.com/p/chinai-323-the-ai-deflation-of...

So a new homegrown chip would have to capture a very large share of this relatively small market to make significant volume. That makes it rather risky for profit-driven investors.

Politically directed investment probably increased, but in the end the private sector also needs to be on board.