LuckyGem is a vanilla survival SMP on 1.21.11 and the map just started so it feels new and open.
It is whitelisted so people have to apply and the community stays respectful and welcoming. PvP is not allowed so it is more about building and surviving together.
It also has Java and Bedrock cross play so more friends can join. It stays semi vanilla with some quality of life plugins and it includes Simple VC for voice chat.
