I found PurpleSMP and it feels simple but still polished. It is a PVE server on 1.21.11 and it has crossplay so you can join from different devices.
The main extra thing here is mcMMO so you can level up skills while you grind resources. The economy is player made with no server shops and no currency so trading is based on what people think stuff is worth.
You can claim land to protect builds and there are player vaults for extra storage. PvP is off by default but you can toggle it if you want to mess around with friends.
They also take safety seriously. Blocks get logged and staff can see backups of your inventory when you join leave or die so they can restore stuff if you lost it because of rule breaking. They say they run strong anti cheat and staff get alerted fast when it trips.
