I try not to make food a struggle. I would serve him something he might eat, something he will eat and a wild card. If you are eating string beans, put a bean on his plate. I would not bribe him but I'd also tell him he doesn't earn a treat if he doesn't eat healthy food.
Last night DD wanted gummies. I said they were a treat and to get gummies she had to eat some of her fajita meat (she ate deconstructed fajitas). She fussed. She cried. I told her that she could be excused from the table (and I would remove her if she didn't knock off the "ew, yuck!" business) but that it was her choice. No meat. No gummies. And I just went on with my meal and ignored it. She stared at those small bits of meat for a loooong time but eventually ate them, making faces all the way. When she was done, I thanked her for eating them and gave her the treat. We don't do desserts nightly so that was special.
If people ask why he won't eat, you can simply say, "This is his choice tonight." Eat what'. served or not eat. If you bring a snack, make it healthy. He eats the pizza served or your carrot sticks.
Now, I have an aunt that will make a kid sit there forever or will reheat food over and over and over and I don't go for that. But I'm also not going to cajole DD and feed her like a baby or make it a battle of wills. She has a choice. She eats or she doesn't, but if she doesn't, then there are rules like no treats, no filling up on milk all night, no snacks. Some nights she might see her sister have hot chocolate and DD doesn't get any - because she didn't eat a reasonable dinner.
I will do trades. My stepson has a weird food textures thing so certain raw foods are just bad news. He always had the option of a salad vs peas. Not worth the gagging. But he had to eat a veggie for a veggie. (This also partially stems from my being forced to eat overcooked canned spinach as a kid....) My DD doesn't like sauce, but will eat her pasta with butter. It'. no big deal to me to put sauce on the side. That sort of thing. We eat a LOT of fruit here, and knowing that DD will eat a whole pint of blueberries by herself, we say she needs to eat her entree first and then she can have the fruit. If she eats a ravioli, for example, she can get a few blueberries.
DD also likes to shop and help cook. Maybe get he picky eater involved in the menu or prep.
I think that they're at an age where they want control and food is something they can control. Our job is to find a balance between starvation (true starvation is unlikely) and overeating on junk, without going crazy or feeling like we have to bribe every bite.
The flip side is if DD says she'. full, she'. welcome to ask to be excused. I will never make her clear her plate for my sake. I offer little bits so she can have seconds, but I don't want the firsts to be overwhelming.
And, sometimes, we make a game. SD, bless her, will say, "Oh, Dad! Can I have a string bean? Oh, please!" and then DD will wonder what she'. missing out on the string beans. Or we'll pretend not to see DD eat and say, "Wait...I put four raviolis on that plate. I'm sure I did! What happened? It'. a mystery!" Then DD will eat another one and I'll turn to DH and say, "Weren't there three raviolis? I'm sure there were! Are you eating DD'. ravioli?" DH will, of course deny it and DD will giggle like a lunatic.