I found this server called Anarchy Network and it is a semi anarchy world that feels really close to vanilla. It started on October 11th 2024 and it runs all the time so you can join whenever.

The server lets you play pure survival with almost no rules. Griefing is allowed and pvp is allowed so you always have to watch your back. There are no map resets so whatever you build can stay there as long as the world exists.

You can join on Java from version 1.7.2 up to 1.21.10 but they say that 1.21.10 is the best so things do not break. The world border is huge at two million blocks so there is a lot of land to explore and hide in.

There are almost no commands. There is no teleporting and no pay to win shop. The only non vanilla thing you can do is use spawn so people that went really far out do not get stuck alone forever. They also let you use the nether roof and they removed phantoms and only half the players need to sleep to skip night.

The rules are pretty simple. You cannot use exploits or dupes. You cannot make lag machines or spam and you are not allowed to harass people or use racial slurs in chat. Other than that the server really just lets players do what they want.