Apart from what others have said. If they pick a different country to fly their yachts flag, they get a lot less regulations. They can hire people from poor country 1, sail around, and if the yacht needs maintenance in a port on another country then they can just fire everyone and leave them stranded in a different continent.
Vice has a video on it.
https://youtu.be/KjpnObVhKpg?si=okTva9gw2w6mukFa
Apart from what others have said. If they pick a different country to fly their yachts flag, they get a lot less regulations. They can hire people from poor country 1, sail around, and if the yacht needs maintenance in a port on another country then they can just fire everyone and leave them stranded in a different continent.
Having serfs at your beck and call raises eyebrows. So they go to sea where there are no eyebrows.