Because they're all that's holding the property together their root systems are exposed on the seaward side, and they are _massive_. I couldn't build a stronger retaining wall. I wish this article shared some pictures of a palm root system, it's really the most impressive part. Together with seagrape shrubs I think I'm actually reclaiming a few inches a year. I also have some great footage of palm trees bent over nearly 90° in a cat-3 from a few years back.
One thing not mentioned here is the risk under storms of coconuts. In a tropical storm, palm trees become coconut catapults when the trunks whip around at high speed and under tension. We've lost multiple 1"-thick concrete roof tiles to coconut strikes, as well smashing (but not breaching) a cat-3 hurricane door.
Here for the Caribbean content!