A guest who lands on your restaurant site and can't figure out how to order doesn't call you. They just leave. The link might be unlabeled, buried below the fold, or broken on mobile. You see lower order volume and blame the weather. The real reason is usually simpler.
Color contrast is the easiest accessibility fix on a restaurant site, and it's the most common miss. Menu text that looks fine on your laptop can be unreadable on a phone in sunlight. A guest who can't read the prices picks the place down the street, and you never hear why.
If your menu lives in an image or PDF on your Squarespace site, guests using screen readers or keyboards can't get to it. Alt text and heading structure are still your job; the platform doesn't flag them. The guest who can't read your menu just picks the place down the street.