Is it impossible to delete a column?

Only the project owner can delete a status or a column from the Board.
Before you delete a status or column, you need to move all tasks to other columns or change their status. You can't delete a column if it still has tasks in it. To delete a status or column:

1. Open the projects panel on SAU.app and pick a project
2. Go to the 'Board' view by selecting it from the dropdown menu under the project name in the header
3. Move all tasks to other columns, dragging and dropping them one by one
4. Click on the black triangle in the top right corner of the column you want to delete and click 'Edit'
5. Scroll down to the Delete button