china has no problem destructively reverse engineering chips. they aren't validating them, they are copying them. and the destructive method may be time consuming, but surely for China it's cheaper?
this technique would be more like CMM validation of a part after manufacturing. very, very useful but with a different goal in mind.
Plus aren't many chips made in China? My impression after watching BigClive tear apart stuff was that a lot of Chinese clones use their own chips, and many chips are custom and seem to only exist between Chinese manufacturers (like custom USB charging chips, led chips for flashlights, etc.)
In order to manufacture these chips you need the schematics. It's the same thing as having the source code and the deployment/compilation instructions: You don't need anything else.
Strictly speaking, for manufacturing you need the layout for the chip, but extracting a schematic from a given layout is an automated process and used for verification. You create a layout from a given schematic and later check, whether the layout implements that schematic.
Physical Unclonable Functions were supposed to address this.
I wouldn't expect them to hold a state actor at bay for more than a little while, but at least with a PUF in place overproduction isn't as simple as "just make more."
And one should not overlook that a lot of cutting edge chip design is done in China. Just think of all the chips by Huawei. On top of that, the direct layout information is more relevant for reengineering than copying.
this technique would be more like CMM validation of a part after manufacturing. very, very useful but with a different goal in mind.