2.5 Year Old Doesn’t Eat

So, we’ve been fighting a battle with my toddler for over a year now and I guess I’m not necessarily seeking advice but more so wondering if others toddlers are the same. My 2.5 year old still doesn’t eat solid food and hasn’t for a year and a half. At around 13 months he just decided he doesn’t like food, so he survives on milk mixed with toddler protein shakes and liquid multivitamins, and he eats 2-4 fudge rounds a day. For 1.5 years now he hasn’t touched a vegetable, fruit, meat, cheese, or any standard toddler food (hot dogs, Mac n cheese, chicken nuggets, spaghetti, etc.)… he won’t put any of it in his mouth.

We have a niece who apparently survived on saltine crackers until she was 8 years old. Should I just assume that as long as he isn’t emaciated he is ok? Maybe once or twice a week I offer him some kind of food other than milk or fudge rounds but he never eats any of it so I am just considering giving up. Is this something where eventually once they can talk they will tell you they want some kind of actual food? I feel bad giving up on my kid but at the same time preparing/cooking and offering food that he never touches just seems like a waste of time and effort at this point.