I'll give it a whack.
First off, I'm defining "good food" rather strictly. Something you'd see in a chef-owned restaurant, where the chef either went to culinary school or worked in prestigious restaurants. (Cooking, like programming, can be learned without school.) I'm not saying they have to have a Michelin star, but they have to be making a real effort to make good food, so not Olive Garden. Most of the people who disagree with me simply don't like my definition of good food (and perhaps find it snobbish) which is totally fine.
So imagine you took a list of everything on those menus, and started filtering out anything using a technique a rice cooker is incapable of. I suppose my statement might not be literally true, there might still be SOMETHING left on the list, but we'd be talking less than a percent.
There are a number of things you just can't do (I think) in a rice cooker that you do at least one of in pretty much every dish you'd see at such a restaurant. You can't cook something at more than one temperature, for instance. You can't cook at any temperature above or below 100 celsius. You can't get a Maillard reaction (the browning of a steak or toast and it's associated flavors) or caramelization to happen. Right there you've knocked out almost everything cooked that you'll see on such a menu.
You can't roast or sear or sautee anything. A rice cooker cooks only with conduction in a wet environment. (I'm assuming convection occurs too when there's still enough liquid in the pot.) It's too hot to simmer and too cold to braise.
Even one pot dishes (and anything that isn't a one pot dish, which is the vast majority of the food I've described, is out by definition unless you have numerous rice cookers) usually take multiple steps. For instance toss the chicken in to brown, remove, sweat some onions, toss in some peppers, put in some plum tomatoes and white wine, raise the heat a little to deglaze and burn off the alcohol, lower the heat, add the chicken back in, braise. Etc. (Season the chicken with salt and a little piment d'esplette in the beginning and you've got poulet basquaise! You're welcome HN.)
So what can you do in a rice cooker? Boil stuff, that's it. You rarely in any decent restaurant will be served something that has had nothing done to it but boiling, in fact, I can't think of anything and like I said, I'm a foodie. I travel around a lot and have been to a lot of restaurants.