Why do you expect that?
Or, perhaps more specifically the guarantee from Article 19, barring segregation from the community at large?
Expecting the declarations on human rights to be followed is not unreasonable.
Nobody "deserves" to go to a resturant.
Regarding nuts, I don't know about the rest of the world but in my country, restaurants are required to disclose allergens in their foods, if asked.
Should all restaurants also be required to serve food for whatever combination of allergies one might have?
My mother has several food allergies, there are restaurants where she can't eat any meal. Would you welcome a law mandating each and every restaurant to start serving meals she can eat?
Suing every hole in the wall out of business is hardly in line with reasonable accommodation.
[0] https://en.wikipedia.org/wiki/Convention_on_the_Rights_of_Pe...
Suing is the enforcement mechanism chosen by the Israelis and the US, not the reasoning behind the requirement. The reasoning is: The disabled should have equal access to dining and it's not an undue burden to expect ramps outside of businesses. Most of the developed world is like this.
You might disagree with that reasoning but clearly a political majority in the US didn't and doesn't.