When I click on a column that has "Click on column header to sort" enabled, I may want to sort by other column values.
For example, the first column is the country name, and the column value is "USA" or "Japan". The second column is the country code, and the column value is 1, 81. The second column is the hidden setting. When you click the header of the first column in this view, it is helpful to be able to sort by the country code of the second column.
I want the ability to specify which column has a value to use for sorting when I click on a column.
I took the country as an example, but there are a lot of things like this.
Displaying values in a view just for sorting purposes can be visually undesirable.