First of all, I try to find a use for everything on this farm. Second, there's very little that I cart off to the dump. So yes, I will use this harvested banana tree.
This particular tree was growing in a hugelpit. Therefore the leaves and trunk will be incorporated back into the hugelpit itself. The leaves and leaf stems go around the bases of the other trees. The truck gets cut up into manageable pieces, which are also placed around the bases where needed. The material in a hugelpit is constantly and slowly decomposing. Thus new material needs to be added. Recycling the spent banana tree helps maintain the hugelpit.
Trees from non-hugelpit locations I often use to help fill pallet grow boxes. I'll cut off the leaves and put them into the box. The trunk is cut to appropriate lengths, which are then put in atop the leaves.
One tree usually adds a single 6"-8" layer to one of the pallet grow boxes. But the tall bananas can make two layers. (I add a thin addition of compost or soil between the two layers to help with the composting process.) So those really tall trees actually do have value over the dwarf trees at times. I know of a lot of people who won't grow the tall varieties.
While I've never used them in cooking, the trunks can be used in imus (an underground cooking pit) to provide steam for the cooking food. I have several people I know who use the trunks for this. They also use the leaves to wrap food in for cooking.
My donkey and sheep will eat the leaves, though not the coarse stems. I understand that the zoos feed the entire young trees to the elephants in order to enrich their lives. It gives them something interesting and enjoyable to do.