إِنَّ الْإِنْسَانَ لَفِي خُسْرٍ
Humanity is indeed in loss.
Exhaustiveness (istighraq) considers all the relevant individuals of a class. The following exception “except those who believe...” provides a strong indication that a universal scope is being contemplated in this verse.
A reference to the essence of a kind is not identical to explicit quantification over all its members. Therefore the article should not automatically be translated as “every” wherever it occurs.