I found a Minecraft Java server that is online all day and night. It runs on version 1.21.11.
It is mainly survival with PvP and a community vibe. They also do events and there is staff around.
It has ViaVersion and ViaBackwards so people can join from multiple game versions. Gameplay is meant to feel smooth.
Join This 24 7 Java Survival PvP
GG.MINEWIND.NET New Server IPUneasyVanilla Semi Anarchy Survival Minecraft Server
UneasyVanilla is a semi anarchy survival server that began on March 10th 2020. It aims to let players experience the game as close as possible to how the developers intended. The server is more lawless than typical survival, but it is not full anarchy. You can play however you like as long as you follow a few simple rules. The server is hosted in Europe, giving players in that region excellent ping and still reasonable ping for players in North America.
GG.MINEWIND.NET New Server IP