As I explained before, it is purely cultural. It is mainly the anglosphere that segregates “breakfast” into a special category of food. For other cultures, it is the same thing you eat the rest of the day.
Some people do eat vegetables for breakfast. I am one of them. I make this kale, garlic, black bean and habanero concoction that is so hot that no one will eat it but me. It tastes fine hot but it is even better if you leave it in the refrigerator overnight. I don’t always eat breakfast but, when I do, that is it.
It is also bullshit that breakfast is the most important meal of the day. American breakfast foods are typically fairly bad for you. You can do your body a favor and just skip them completely. Nobody is going to starve to death just because you slept for a few hours.
Also on the NEVER list: green peas, brussel sprouts, asparagus, okra, eggplant. And add to the RARELY (but only in an omelette or quiche) list: spinach.
Can you show me an example of a culture where they routinely eat salad, or broccoli, green beans, cauliflower, carrots, corn on the cob, or cucumber, or green peas, brussel sprouts, asparagus, okra, or eggplant, for breakfast? FWIW, I admit that I’ve only ever visited countries that are in Europe or were settled or conquered by people from Europe. I admit I’ve never seen what people eat for breakfast in Mongolia, for example.
All of those are a very Anglo view of what food is. Some people have trouble even comprehending that ‘breakfast’ isn’t a special category in most of the world. It is very odd for it to be considered so if you think about it. Part of American breakfast thought comes from England and Ireland but other parts like breakfast cereals were invented as a genuine cult movement. John Harvey Kellogg was a flake and helped invent the cereal industry as part of his own spiritual/religious/vegetarian movement. There is no reason for American supermarkets to have a whole aisle devoted to cereals except because of this one extremely influential zealot from the 19th century.
Try a google image search for “Japanese breakfast” and you’ll see it almost always includes vegetable side dishes and pickled vegetables. And often soup with some vegetables in it. Even the “western” breakfast served in Japan usually includes vegetables - e.g. the second photo here.
In fact, just try Google image searches for <name of country> + breakfast. Most will include vegetables.
That article is actually titled “50 of the World’s Best Breakfasts.” Best as judged by an American writer, it appears. It is heavily biased towards the kind of breakfast Americans find appetizing.
Our morning smoothie always includes kale. We often have vegetables at breakfast, though not exclusively. As mentioned above, in many cultures, breakfast is reheated dinner.
I am pretty sure that the grand majority of people on the planet have never met a Jewish person. I wouldn’t be surprised if the majority of English speakers haven’t, either.
All this discussion and no one has brought up huevos rancheros? A favorite breakfast item of Mexico and many places in the Southwest, it has plenty of veggies: beans, tomatoes, onions, peppers, and avocados.
