Sitting Down
Sitting down would be a state a player can toggle into, increasing health recovery and reducing stamina loss, in exchange for not being able to walk/run/jump.
This is only possible on certain non full blocks, slabs, unlit campfires, snow layers pas a certain height, stairs etc.
This would require a slight nerf to Java saturation regeneration because boosting it beyond where it is would be broken.
On bedrock this would be a way to regain health in under a minute.
The lower stamina drain would be useful for farms, and sitting down to do a task would be more immersive too.
Players would be incentivised to set up seats, benches, rest stops etc around their world.
Knocking a player off of, or destroying the block they're sitting on would force them into a standing state.