Unless its a national chain, the ones in my area are either building it from scratch or using a template. The made-from-scratch are painfully obvious in that they look like some high school student with a touch of experience cobbled it together. And that's probably what happened - the owners child or niece/nephew did it.
The template sites are obvious because the owners chose a feature-filled template with all of the bells and whistles but have no use case for all of the frills. There are empty carousels, tons of extra white space, empty link slots, and a halfway responsive mobile experience.
Considering the above, a static, zoom-able HQ image of the menu is not a bad option. It's not optimal, but it's not bad. It tells the restaurant's name, phone number, business hours (possibly), address (again possibly), plus the entire menu. That ticks all of the major boxes for information that a customer may need.
The template sites are obvious because the owners chose a feature-filled template with all of the bells and whistles but have no use case for all of the frills. There are empty carousels, tons of extra white space, empty link slots, and a halfway responsive mobile experience.
Considering the above, a static, zoom-able HQ image of the menu is not a bad option. It's not optimal, but it's not bad. It tells the restaurant's name, phone number, business hours (possibly), address (again possibly), plus the entire menu. That ticks all of the major boxes for information that a customer may need.