I found a server called MinecraftOffline that runs on version 1.21.11 and it is made for people who want a world that sticks around.
The map is permanent so it is not getting wiped all the time. It also uses a custom plugin suite so it is not just plain vanilla.
It is based in Finland so it should feel good for players in Europe. The server also says it runs on reasonable hardware and that helps keep things stable.
MinecraftOffline 1.21.11 Permanent Map Server
GG.MINEWIND.NET New Server IPFresh Java SMP Seeking Friendly Players
I found a brand new Java SMP running on Minecraft 1.21.11. It is meant to be small and friendly so people can just play and hang out.
It already has EssentialsX and GriefPrevention set up. That means you can get some helpful commands and also protect your stuff from griefing.
The owner is pretty new to running a public server and says they are open to suggestions. They want a happy balance and better communication and they might start a Discord for it. Just do not be weird.GG.MINEWIND.NET New Server IP