Standard activity completion offers the 'Require grade' criterion by means of which the activity may be classed as completed only if the participant has a grade for it. But that would be for any grade, even 0, in which case a failed activity may still be rendered completed, and from experience this may be quite confusing for participants.
Completion by specific grade is probably particularly relevant in use-cases where there are multiple gradable elements and where multiple elements could be graded over a period of time. For instance, you can deliver an activity where participants submit weekly short paragraphs, each paragraph may be marked Integrated if selected for integration with the project masterpiece, and participants have to have at least 3 paragraphs integrated for their activity to be considered complete.
It is quite possible that at some point the standard Require grade completion criterion will allow specifying a target grade. In the meantime the Dataform will offer a module-specific criterion for this purpose - Require specific grade. In 2.6 it is applicable only for the Dataform calculated grade. In 2.7 it applies more generally to any occurrence of the \core\event\user_graded event, e.g. when updating Dataform grades directly in the gradebook.