Web devs aren't forced to deal with accessibility either, unless they choose to work with or for an entity that requires it. No one is coming for your self-hosted blog because its not ADA-compliant.

But if you want every restaurant to be forced into labeling, you will see the small restaurants claim all the allergens are used and they cannot protect against cross contamination.

The FDA prohibits blanket labeling of allergens. They might be able to get away with it but it wouldn’t be legal.