This is a benefit of having ultra dense industry specific zones like the Shenzhen SEZ. Physical vendors get the volume to warrant operating and reasonable pricing, buyers get components on short notice.
Suburbanization set up the US for failure here, and the governments haven't bothered intentionally creating any equivalent of Shenzhen. Santa Clara county used to be the spot, and I'd regularly pick up quickturn PCBs in person. Still can, but if you're in SF you're probably going to wait for next day shipping unless it's super super important, in which case it could come from any domestic CM.
The US used to have its own SZ in lower Manhattan. They were abandoned when Japan did things cheaper.
This doesn't really solve you problem, but they did just open (or about to) a Micro Center in Santa Clara.
Is it just about having dense industrial zones? I would have imagined cost of labor to be the major cause of price differences.
A lot of the cost of silicon valley labor comes down to extremely high housing prices. A lot has been made of how the tech boom was simply a wealth transfer from investors to bay area real estate + homeowners.
Sure but even if you exclude Silicon Valley, the minimum wage for a US worker must be a fair bit higher than the equivalent non-US worker.
The public's (lack of) tolerance of pollution also impacted things. It's not like PCB manufacturing is clean.
PCB manufacturing isn't that bad, semiconductor fab is very nasty. It was nasty an unmitigated way during the birth of silicon valley, check out a superfund site map if you're bored.
https://www.arcgis.com/home/webmap/viewer.html?layers=c1229e...