Rainbow Unity is an SMP that is updated to 1.21.11 and it is built for people who want a place to settle in.

You can claim land so your stuff stays yours and you can build up an empire over time. There is also a rankup system with perks so you can keep leveling up while you play.

I also saw crates for powerful rewards plus daily rewards to keep you coming back. It has ranks quests custom items crates and land claim so there is always something to do.