Yes, building in a flood plain is stupid unless you build to withstand floods, which is cost prohibitive for most.
Building on a raised foundation is not that costly, just raise it on wooden pilings eight or ten feet and park your cars beneath, that’s how practically all beach cottages are set up on the southeast Atlantic coast. Some go further and have a raised garage or parking area so their vehicles are above the 100 year flood plain, historic storm surge averages or whatever standard they’re going by.