Water constantly and evenly rising without any other nasty effects over years/centuries is a massive oversimplification. Far more people will be at risk all through the way to that, how many people would survive in your area if just one of the days of all those years gets to, I don't know, 60ºC? Even 40-50ºC with very high humidity will do the work. And massive rains, or hurricanes or other extreme weather events. No matter how safe are you from sea rise, is the whole pack what put your life at risk.