For some fields types “required” does nothing. When creating a new field the first 5 settings (up to required) are standard settings for every field. Also the last 2 settings (conditional logic and wrapper attributes) are standard for every field type. All of the fields in between these are dependent on the field type. There are only a few fields where required has no meaning and I assume that it’s easier to include it everywhere then to make that setting a field type dependent field.
