It was how restaurants worked for a long time. Of course, if you prefer the predictability of seeing the menu before you get there, that’s your preference, fair enough. But I wonder if you might miss out on some places run by cooks who put all their talent into cooking, and none into technology. Could be some good stuff…
Example of how this falls apart: you change your prices. You change your menu. You have different menus for different times of day. You have different menus for special occasions.
Good point. Also, once the customer is accessing the menu through their smartphone, modern ad tracking technologies also enable pricing to match the expected buying power of the customer. This way the hospitality industry and their adtech partners can extract more value from the transaction and thus increase the efficiency of the market.
AFIAK those pictures-of-menus don't come from the restaurant owner, but from the people dining there. I believe they're partly scraped from restaurant review sites like Zomato (where the pictures-of-menus are interspersed with pictures-of-the-food-itself) and partly the result of Google doing Google Lens things to your Google Photos to figure out that you took photos while inside a restaurant, and then asking you if it can use them.
Market forces are made of people. You can't just abdicate responsibility for your actions by saying "I'm making financial actions, therefore it's the invisible hand doing it, woooo!".
It's not that big of a risk to be honest. People did it all the time before the internet. Some people are not pathologically risk adverse and might even enjoy being surprised.