Q.Benjamin ficus tree
My ficus tree has lost all its leaves, is there still life in it or is it a goner?

Do the branches bend or snap off and break?
You can scratch the bark and see if it is still alive.
If the branches and trunk are still alive, a Ficus can recover from leaf loss.
These links have more information on the care needed.
https://www.gardeningknowhow.com/ornamental/trees/tgen/tree-scratch-test.htm
https://www.gardeningknowhow.com/houseplants/ficus/ficus-tree-care.htm
https://www.gardeningknowhow.com/houseplants/ficus/ficus-losing-leaves.htm