They’re lower and wider than drink cups and nestle nicely into your car’s cupholders to hold the chicken and French fries you just drove away with—which is an easy, basic brilliance that took a long time to arrive, it seems to me.
When you’re the driver, one-handed chicken tenders/ nuggets/ planks/ sheafs/ whatever-you’ve-named-them and fries (which might as well harmlessly co-mingle) are an easy and safe choice: keep one hand greasy, the other clean for gripping the wheel. But as far as I can tell, KFC is first to the mass market with these little ergonomic wonders.
Goes to show there’s always room for innovation. I’ll bet whoever came up with those was new to packaging, new to QSR, or in school. That’s just a hunch. Whoever developed these, they approached the problem of driving-and-eating with beginner’s mind.