I found 1fighter2defenders and it is a survival server that tries to stay as vanilla as possible.
It has no gameplay rules at all. There are no admins. There are no land claims and no protection. Griefing building and cheating are all allowed so you kind of have to watch your back.
They also say there are no server sided dupes and no world resets. The server started in April 2021 so it has been around for over 4.5 years with lots of people joining at least once.
It runs on 1.21 and it lets you join on 1.17 through 1.21.11.
