There are something like a hundred chip factories across the world. TSMC itself has around 20 (mostly in Taiwan). One dying would definitely raise prices, but we won't be losing 'most modern technology'. And of course they'd have lightning cables; they aren't idiots.

they almost certainly have lightning prevention measures on those fab buildings. It'd be stupid for them not to, stupid to the tune of 10s of billions of dollars, and a global collapse of the chip market.

First of all, it's not the "world's only chip factory". Maybe for some bleeding edge node like 2 nm, but most photolithography systems use larger feature sizes. Secondly, lightnings haven't been an issue anymore for more than a hundred years now.