GoblinSMP is a vanilla focused survival server with a semi anarchy style. It feels like regular Minecraft where you actually have to watch your back.
There are no land claims or protections so people can build raid trade team up or betray you. The world is compact so you run into players a lot and things can get tense fast.
The main rule is no hacks or exploits. It supports Java Edition and it runs on 1.21.11 and you can join on any version. The server is hosted in the United States.
I found a Minecraft anarchy server that runs on 1.21.11 and it is built for lifesteal style fights. It is the kind of place where people actually want chaos and you have to watch your back.
The world is eternal and they never reset it so your progress can stick around. The gameplay is boosted with custom made plugins so it feels more intense than plain survival.
It is hosted in Finland so it should feel smooth for a lot of players in Europe. They also say the hardware is reliable so the server can keep up when things get wild.