Earthquake risk in CA is very exaggerated. I grew up in Yolo County, which is in the Central Valley. In the 15+ years of my childhood that I can remember I never felt an earthquake. In the decades after I moved elsewhere my parents did not feel any earthquakes, though they knew of the 1989 Loma Prieta earthquake from the swaying of some decorations. They lived ~70 miles from the nearest significant fault, and ~150 miles from Loma Prieta. My home in 1989 was about 25 miles from Loma Prieta. We lost electrical power for a couple of days, but I don't think anything fell off our walls or from our cabinets. California construction standards have evolved through the decades since the 1906 earthquake, but the post-WW2 construction I've lived in since moving to Silicon Valley during Carter's MalAdministration has held up well.

As for California falling into the ocean due to the San Andreas Fault, which many conservatives seem to with for, the San Andrea Fault veers into the ocean at SF, follows the coast northward to Point Arena, and then veers out into the ocean. IOW, SF is east of the San Andreas, as is most of California.

I have relatives who live in NE Kansas. They occasionally commented that they could not imagine living in "earthquake country". This amused me, as they spent a good part of every year with an ear on the radio or the Weather Channel, listening for tornado warnings. Every. Year. In the same way, the Gulf Coast has its annual hurricane season, and every few years a hurricane tears its way up the East Coast (e.g. Hurricane Sandy, which clobbered New Jersey). Basic reality is that every area of the world has some sort of natural suck.

Yep, every place has its own version of suck, but some situations are far worse than others, others more predictable.

Maybe California was a bad example...maybe not: (from Google's AI search of quakes around 7 in magnitude)
1989 Loma Prieta
6.9 magnitude earthquake that killed 63 people, injured 3,753, and caused up to $10 billion in damage
1994 Northridge
6.7 magnitude earthquake that killed 57 people, injured 9,000, and caused up to $40 billion in damage
2019 Ridgecrest/Trona
7.1 magnitude earthquake that preceded a magnitude 6.4 quake and had no fatalities

Already worse than this area of the Appalachians in terms of damage in the last 100 years from hurricanes, and only going back 35 years. It is entirely possible the number of dead from this storm will be multiples of all of those events put together--much depends on rescue efforts.
You may be used to what happens there because low magnitude quakes are common and damage mitigated in those because of construction codes, but the folks of Western NC/Eastern TN have not had anything like this in living memory, and its effect is compounded by the dependency on technology (electricity, communications, driving to the store, etc.) that has come about since the last disaster which translates to increased vulnerability, not less. People were more 'bush' capable and self sufficient last time around.
Add in that there is nothing that can resist the force of that much water (25' over ordinary spring floods) moving fast--flash floods along two rivers accompanied by landslides from the saturated ground. The roads and towns are in the bottom of the valleys, the utilities often follow the roads and the roads washed away.