Not like earthquakes are unheard of in Taiwan or South Korea either.
Buildings are going to be more expensive (base isolation and an extra commie blocks worth of reinforced concrete), but given how expensive fab equipment is, that might not even matter all that much.
South Korea? Almost nil. It's not known to be a seismological region.
Taiwan, Japan have far more exposure to a long history of earthquakes, tsunamis.
For Taiwan, there is another existential threat man made.
Earthquake isolation can be pretty amazing. Here’s a video of a data center during the big 2011 quake. The camera is attached to the outer wall so the point of reference makes the wrong side look like it’s shaking, but you can see the people walking without difficulty during some pretty heavy shaking. A fab will have even better stuff.
https://youtu.be/GXwQSCStRaw