There needs to be a unwritten social rule that states that if you're allergic to everything, you need to bring your own food to events.
As a person with severe food allergies, people who act entitled like this (expecting others to meet their special needs with no advanced notice) annoy me to no end. The root of it is a lack of personal responsibility; these people expect the world to cater to them. I've worked in the food industry & have no illusions about what goes on behind the scenes. Unless the restaurant is specifically advertising allergen-friendly dishes, you have no guarantee that the food will be safe, therefore it is your own fault if you willingly ingest food that you haven't personally verified is safe. Technically sure, a restaurant should cater to your needs, but if it's something that is going to
literally make you sick if you eat it, that's not something that should really fall under their jurisdiction since it's a busy production environment, not a sealed-off cleanroom where they carefully ensure that allergens don't get into the food like in a food manufacturing plant for processed items.
That's not to say that companies aren't stupid, either. Dominoes Pizza got in a heap of trouble with the Celiac community when they released their gluten-free pizza crust...sure, technically the
crust is gluten-free, but it's prepared on shared tables, cooked in shared ovens, cut with shared utensils, so there's lots of cross-contamination. I have a friend who ends up in the hospital if she eats anything with gluten, so that's a pretty rotten thing of Dominoes to do - advertise that they have a gluten-free product that isn't really gluten-free by the time it gets to your plate.
So it's a buyer beware world out there for people with food allergies. The name of the game is be courteous & come prepared. There are a very limited number of local restaurants that can deal with my food allergies and I usually build up a relationship with their workers, like my local sushi restaurant knows to always use gluten-free soy sauce, no crunchies (wheat), etc. And if you're going to show up somewhere, bring your own food if you don't know if it's going to be safe ahead of time. Common sense. Not so common haha.