I remember when I was a kid in the 80s, they would advertise cereal as being "part of this complete breakfast," which was supposed to be cereal with milk, toast, a glass of juice and a glass of milk. And even as a kid who would eat a meal of practically any size put in front of him, I was like, "who is having all of that at breakfast?!"
Edit: I forgot! Also fruit! There would be like a whole banana next to the cereal bowl!
Yay, marketing. The nutritional value of the cereal is probably next to nothing, but if you ate everything else, you'd get all the nutrients you'd need. 1% of the total is still "a part" of the complete breakfast. Technically not false advertising.
Basically, the more food you see, the less nutritional value in the actual cereal.
Frosted Flakes is savory compared to some of those other cereals. Froot Loops is like just pouring a sack of sugar in your mouth. It also has a mascot and, unlike Frosted Flakes, it comes in lots of fun colors to appeal to kids.