China is also short on supply... Capex for these are planned years ahead and just not flexible enough to deal with the supply squeeze right now.

I'm not sure that's going to change unless the LLM stuff slumps. Chip makers get burned every few decades by building boom-time capacity that comes online just after the crash. They're going to be reluctant to make big capex spends unless they think the demand is durable.

China is famously fast at building things, but maybe not semiconductor factories... especially with long lead times from Western suppliers.