I think you mean that rhetorically, but a lot of folks who live in flood-prone areas (which can be well-inland, not just rich coastal places) didn't make that decision recently, and can't afford to just move to solve the issue.
We're in a flood zone, 2 miles or so from the ocean, along with millions of other folks. We have lived in this house for about 20 years, and I've been in this area for 40+. Never had an actual flood event. Hurricanes, sure, but no water in the house, no water that didn't recede and leave streets drivable 24 hours later.
Meanwhile, a small Tennessee town flooded this summer, for the first time in 100 years.
And there were significant flash floods in Tuscaloosa, AL, just a couple of weeks ago.
Neither of them would be considered highly attractive or communities too rich to subsidize.
(PS, I'm not debating whether subsidies should exist at all, I think that's an ideological debate that won't be won, just trying to add some "not everyone in a flood zone is a rich person with options" to the mix)