On the Richter scale, the difference a full step (7.0 to 8.0) is about a factor of 32. So if we're trying to mitigate an 8.0 earthquake every 100 years, you're talking about a magnitude 7.0 every 3 years to release the same amount of energy.
Most engineering structures on the west coastare built to withstand a 6-7. When a magnitude 8 comes (and it will come, and in some sense we're coming out of the stress shadow from the 1906 quake just now) the devastation will be horrendous.
*Editting to add:
The structures on the west coast are engineered to withstand a SINGLE 6-7 magnitude event. Not one every 3 years.
And even if they were built to withstand a mag 7 earthquake every three years, the things inside of them likely won't be. Imagine the engineering that would have to go into designing every single item in your house to withstand a deadly earthquake on a regular basis. No more popping out to Ikea to grab the same furniture everyone else uses. Your TV stand is on springs. Your TV is on springs connected to the TV stand on springs. Your cupboards have notches where your dishes can lock into them so they don't slide. The cupboard doors have latches that let them open when pulled slowly, but resist opening when sudden force is applied. Your refrigerator bolts to the floor and is filled will elastic pockets that hold every item individually.
Its either that, or spend a significant amount of time every few years packing all of your items into boxes to ensure they won't be damaged when it's earthquake time.
My mom's strategy for the biggest items: lash them to the walls so that they don't topple or walk out of position. This doesn't solve the problems of falling plates, but it does mitigate death-by-cabinet.
That said 80% of the benefits are in location. If you're on flat bedrock, located away from the coast, you just don't feel the most intense shaking, and you won't face a tsunami.
Most engineering structures on the west coastare built to withstand a 6-7. When a magnitude 8 comes (and it will come, and in some sense we're coming out of the stress shadow from the 1906 quake just now) the devastation will be horrendous.
*Editting to add: The structures on the west coast are engineered to withstand a SINGLE 6-7 magnitude event. Not one every 3 years.