At the moment a cell is either driven through formula, and is uneditable, or is editable.
This particularly becomes a hassle if you want to display or style the value in some way while still having it be editable. Formatting gives us some control, but only limited:
One use case is where the community has hacked around the issue of wanting to display a hierarchy beyond a single layer deep (using Grouping). The solution there was to have a Parent and Name column so you could edit both values, and then another column that offsets the Name value based on the depth of the parent hierarchy:
In the above example, only Parent and Name are editable, which means I need to display Name if I want to quickly add in rows or edit them. If the Name column could have a style or display formula that does this, and double clicking would give you the editor for the underlying value, this would be handled.