I see why you're confused. Some of these tags carry nutritional information, so it's easy to assume they all do.

The healthy tag is about marketing. It's a product positioning statement.

I'm guessing that if it is a real tag, then consumers have a "know it when I see it" feeling for certain kinds of food that they'd describe as "healthy." As a word that could be consistently well-defined, it's garbage. But that doesn't mean it's not useful for real-world consumers to find what they believe they want.

If I search "healthy" in DoorDash, Taco Bell comes up in the top results