[Edit] In the US [/Edit] your home and office are most likely already set outside the floodwaters of the 100-year storm. New roads are typically designed to convey floodwaters at no more than 1 foot deep for the same event.
Protecting a building that has a lifespan of less than 100 years against an event with a probability of occurring between .005 to .002 (the 200-year to 500-year event) is a hard sell.
Only in America. The Delta Works in the Netherlands are designed for the 2000-year flood. This is the minimum - there are areas that are protected against the 10000-year flood.
This makes sense. It is not normal that densely settled areas are flooded at least once during the human lifespan.
You don't seriously claim all of Europe is prepared for a 2000 year flood. I doubt a lot of nations can afford it.
It is not only protecting the building; it also protects those living in them.
Also, you should use 'expected damage done', not 'life expectancy of hardware' as your metric. Rebuilding your house may cost you a year of productivity. Rebuilding a hospital or factory will easily take more.