There's some kind of appeal to having a Minecraft Robinson Crusoe experience with a long island out at sea. Survival island seeds are fun, especially when playing on hardcore mode. Almost every survival island seed now can turn into island hopping if the player chooses to leave the initial island. Luckily it is still possible to find survival islands, but that's usually it, it's usually a few islands. Unfortunately this change made Minecraft survival island seeds extremely rare, especially the lone island seeds. Starting with Minecraft version 1.7, oceans became much smaller and islands more common. This Minecraft seed page is dedicated to survival island seeds.
Wolf-infested survival island with ocean monument