celebrate treats. I’m not sure I would agree that kids don't like good food but do agree they can drive you nuts over their requests. I think we all celebrate treats more than average fare we eat & kids are no exception. Since the average toddler only eats robustly 3-5 days a month, their picky nature is often bypassed if you offer their favorite. If the kid is growing well and plays hard stick to the good foods.
Picky eater. Most kids don't even recognize healthy vs not healthy. They recognize taste. Seriously, which would you rather have, a cookie or a green bean? Just keep introducing all new foods, neutrally. Hide veggies, like blend a zucchini, and add to spaghetti sauce. Encourage one bite. Only give junk as a special treat. If they totally reject them, give them a multivitamin. Just keep trying. .