Eucalyptus - There are lots of species, and I’ve burnt lots of different ones over the years.
Generally they burn hot with good coals and no spitting. To get the best firewood out of them, split the wood when its green and let it dry out for 6 to 12 months. Then burn it.
The timber’s produced are hard. They are generally sawn green, the ends are sealed and then they are stacked to seasoned (the old rule to thumb is an inch per year). The wood produced can vary from white, golden hues, to pinks and reds.
In my part of the Australia, Mountain Ash is very common, they easily grow 60 or 70 meters and some of the largest (still living) ones are over 80 meters !
Apart from burning and timber (for furniture and construction), the dried wood is often turned, especially if its an interesting piece.
From a bushcrafty point of view, you could carve a coolamon bowl, a hardwood spear point spear (to attach to a light weight shaft), a woomera, club, bullroarer, digging stick etc
I carved (chipped) a wood working mallet from a lump of red gum. Handle and “head” all in one piece. It is very dense, heavy, red coloured timber and perfect for the job.
Some species make a fair tinder. The bark can be roughed up to make a “birds nest”; one advantage is that only the outside gets wet and the inside is always dry (if you pull the outside off).
Stringy barks (trunks) can be peeled to produce sheets of bark for construction jobs (if you have seen old photos “bark huts” in colonial Australia); but the sheets can also be used as mats etc.
Some young saplings can have the bark stripped to use for cordage (a bit like a willow).
So there are lots of possibilities ...