Given the linked article is about a 22 year old making a 1,500 transistor IC, etching wafers for a 40 year old with a FAANG salary doesn't seem that far fetched!

It'd have to be a really clean garage tho

I think the CNC part is what’s interesting. A wet etch, or even a plasma etcher, is conceivable in a garage and are the traditional tools of the trade.

I assumed that they must have meant milling PCBs, because the only kind of “cnc-ish” way of manipulating things on wafers I can think of would be atomic manipulation with a scanning tunnelling microscope, which really doesn’t seem likely!