I found LegionCraft and it is a OneBlock survival server where everything is about building up from a single block and pushing your island forward.
There are challenging bosses and when you beat them they can drop keys for rare loot. You can use keys on crates to get gear and rewards.
It also has chunk hoppers so you can automate parts of your island. The server says it is not pay to win so it feels more fair while you build grind fight and loot.
OneBlock Boss Fights on LegionCraft
GG.MINEWIND.NET New Server IPLegionCraft OneBlock Crossplay Boss Loot
LegionCraft is a OneBlock survival server where you start with one block and keep grinding to grow your island. It feels like every block matters because you are always pushing for better stuff.
There are challenging bosses and they can drop keys so you can chase rare loot. You can also open crates for epic gear and rewards.
The server has custom enchants and spawners to help you build up faster and get stronger. It also has custom OneBlock islands so you can expand and try to dominate your world.
It supports cross play on Java and Bedrock and it is marked as not pay to win. Version 1.21.11 is listed.GG.MINEWIND.NET New Server IP