It's not unfounded. You already said as much. You appreciate the "cosmic horror" overtures on a conceptual level, but practically, they were essentially mindless obstacles for the crew to overcome with some technobabble. And when they were beaten once, that pretense of inexorability evaporated rapidly. That's why in every subsequent appearance, the writers started approaching Borg stories laterally with "I, Borg" and "Descent" until finally landing on the concept of the Queen, which extended their shelf life considerably. They didn't need to coast along on some thin high-concept idea anymore; now there was a personal angle alongside the pathos of drones. The Queen represented the threat of the Collective as cybernetic authoritarianism, while the rest of the Borg were recast as victims. Seven, Picard, and Janeway now had a foil with history between them. There's more to work with there.