I found Eternal Region SMP and it is a Java server on 1.21.11 for ages 16 and up. Season 3 is back and it goes for that classic SMP feel with a long term world.
It plays mostly vanilla with small upgrades. You can run shops do PvE and only do PvP if both sides agree. They also do community events and they even vote on features and choices.
Phantoms are turned off and you get phantom membrane from bats instead. Creepers and endermen cannot mess up your builds. The overworld has a 10k border so the world stays tight.
They support Simple Voice Mod for in game chat. They also use CoreProtect so grief and theft can get handled fast. The server feels rules focused and community first.
Classic Vanilla SMP Season 3 Revival
GG.MINEWIND.NET New Server IPCommunity Vanilla SMP Looking For Players
I found a vanilla survival SMP that is trying to pull together about 25 to 30 players to start a community driven world.
The vibe is chill and focused on building and playing together. There are clear rules like no PvP unless both people agree. No griefing. Also just respect other players and their builds and boundaries.
If you want a simple vanilla place with a bigger group and basic respect rules this server is aiming for that.GG.MINEWIND.NET New Server IP