It would be great to be able to draw dependencies directly on the Gantt chart view. Right now the Dependent column works exactly like the Connect Boards selector, you scroll through the list and pick the task by name. When you are viewing them in the Gantt view, to set a dependency you would have to click the task to get the popup menu, then edit the Dependent column with the list picker, it’s not a very smooth experience.
Here is a quick loom of how it works in Wrike. This is a great experience for building out the Gantt chart in a visual way: Loom | Free Screen & Video Recording Software