“Try having that attitude when you can’t get a kid who’s melting down to eat anything.”
That’s what I’m told when I opine that it’s all about what kids are exposed to, and parents’ commitment to teaching. Infants in the South Pacific are given some fish oil in their baby formulae, because if you won’t eat fish in the South Pacific you ain’t eatin’.
If we kids ever got finicky, my dad would say, “OK, don’t eat. You’ll eat when you’re hungry.” We ate. And we mostly will eat (and seek out) anything to this day.
Kids eat what they’re exposed to, plain and simple. Not that they’ll eat and love every single item the first time it’s offered, but it’s how their general preferences are formed. If they’re fed a diet heavy in fats, sugar, vegetables, meats, bland foods, spices, etc., that’s what they’re going to like. Kids (or anyone really) are picky when they have the luxury of choice. Imagine a kid in some rural African village saying “meh, I don’t like goat meat” and choosing to starve because no one will bring them chicken nuggets.

Unlikely to happen.
Last week I heard this story from a mother who volunteered in my son’s classroom. They were doing a science lesson involving lima beans. The teacher asked the class, “Does anybody like lima beans?” All the kids started with “Ewww, yuck!” and my son raised his hand and said “I love lima beans.” Lol. I replied that being vegan, my kids didn’t have the choice to not eat their vegetables, or they wouldn’t have anything to eat at all!
I once read that we need up to thirty exposures to a new food before we develop a taste for it, so that’s what I tell my kids. You don’t have to like it, you don’t have to finish it, you just have to try one bite of it tonight… and the next 29 times we serve it.
I have a personal, unfounded, based-on-nothing theory that formula and store-bought baby foods are working against us when it comes to getting kids to develop a varied palate. Nursing babies get flavors in the breastmilk from foods the mother eats, so they’re being exposed to different tastes with each meal, from birth. Formula-fed babies are getting the same taste over and over for however long they’re on formula. Babies who transition to eating solids off their parents’ plates are being exposed to a wider variety of flavors than babies who are transitioned to premade baby foods, which generally seem to be limited to a dozen or so flavors. I think the limited flavor exposure probably contributes to pickiness in the toddler years, whereas a child who has had exposure to a greater range of flavors as a baby will probably be more willing to accept those foods as they get older.
(To head off possible controversy: Yes, formula is a healthy, wonderful, and sometimes necessary choice for babies. I’m not criticizing that choice, my own children have been fed formula. And yes, I know there are certain behavioral and medical issues that contribute to food pickiness in children; that’s not the kind of pickiness I’m referring to in my post.)