> If I eat bland things, sure over time I may adapt to it.

I think you're arguing with the GP comment, not my comment. The kind of "diet" being described in my comment above—if you even want to think of it as a diet—doesn't actually stop you from eating anything, if you count by "flavor experiences" rather than "meal experiences." It just makes you get your "flavor experiences" separately, rather than all at the same time. (Or "as separately as you can." A food with N-1 macronutrients is still going to fill you up faster than a food with N macronutrients; so just minimizing macronutrient variety per meal is fine. You don't have to strictly limit yourself to some small number. Eating a salad with dressing as your meal, is still better than eating a salad with dressing and meat in it.)

Most foods invented throughout history actually already fit this "diet." Vegetable soups, however many ingredients, still have only two or three major macronutrients. Roasted poultry only has one. Mashed potatoes only have two. A steak has one. Fruit pies have three. Nigiri sushi has three. Most authentic italian pastas have three. Even "bad for you" foods like hot dogs or mac-and-cheese only have three, if you make them from scratch.

There are two types of recipes that have high macronutrient variety: those invented throughout history to be served to nobility/royalty, that were "fancy for the sake of being fancy"; and those invented in the modern era of year-round grocery-store ingredient availability (and thus no need to work with what's in-season, freshly-harvested, before it rots.)

Sandwiches, hamburgers, American pizza, "tex-mex" tacos/burritos, and other food-court staples: nine or more macronutrients each. The kind of cheese powder found in doritos or shelf-stable mac&cheese counts for eight by itself! The average take-out order of "American Chinese food" hits almost a dozen. Most French sauces reach seven macronutrients on their own, before counting what you're putting them on. A full English breakfast has twenty macronutrients.

Some of these are capitalism at work, creating ever-greater superstimuli out of originally-simpler meals (e.g. pinche tacos; authentic regional Chinese cuisine; etc.) You can just buck that trend, and be healthier for it.

But for some of the others, the macronutrient-variety is fundamental to what the food "is." In those cases, keep in mind that most of the food experiences these foods give you, are made up of—"synthesized" from—simpler standalone food experiences, that just happen to be happening at the same time in your mouth, without really being one unified food experience. You can have the experience of eating just the "melty cheese" part of a pizza—that's raclette. You can have the experience of eating just the meat part of a hamburger—that's a hamburger steak. A loaded twice-baked potato breaks down into two separate meals: baked potatoes + sour cream, and a pasta-salad-like dish. Etc.

None of these are "less tasty" when taken separately. They're just different ways of having the same experiences. If you like, you can eat garlic bread for one meal, a Greek salad for the next, and charcuterie for a third—and you'll have "eaten a pizza" of whatever toppings you like. (Personally, I'd rather just eat a simple caprese pizza, which has ~5 macronutrients; but if you prefer the complex flavors, go ahead and have them. Just—separately.) Likewise, if you're getting American Chinese take-out, you can just eat one of the dishes you ordered per meal, rather than trying to have a little bit of all of them each meal. (Some of those dishes are, individually, pretty macronutrient-rich, but if you want those flavors, this is how to get them.)

Of course, you can have complex foods if you do it as an indulgence, the way people think of ice cream (which is actually not an indulgence under this paradigm; you'd get full on a meal of pure ice-cream quite quickly, if you were just eating from hunger, rather than stress-eating.) You'd just have to be consciously aware that your body isn't going to correctly estimate when you've had enough everything-pizza, and so you'll have to consciously limit your intake rather than relying on satiety in that case. You'll likely end up somewhat hungry after such a meal. That's fine—you'll get to feel full again soon-enough, as long as your next meal after that is a low-macronutrient-variety one.