I found a public SMP for Java 1.21.
It is a simple survival multiplayer server that is open for anyone to join and play.
Public Java 1.21 SMP Just Opened
GG.MINEWIND.NET New Server IPCozy Semi Vanilla Java SMP
Chill building timeFriendly Survival Worldlaid back multiplayerSemi-vanilla survivalsimple survival gameplay
I found a simple cozy SMP that is semi vanilla and runs on Java.
It feels like a straightforward place where you just join in and play survival with other people. The whole point is keeping it cozy and easy to get into.GG.MINEWIND.NET New Server IP