my local restaurant served me recently some wild salmon (slice) from the grill. It tasted delicious, but was pretty dry. I'm aware that wild salmon has much less fat. So I'm wondering, is there any preparation or cooking technique for barbecuing wild salmon on the grill to avoid that the fish gets dry? note: Placing the grill a bit higher, is not an option for a restaurant, where they grill several kind of fish at the same time P.S.: there is a similar question here, but the answers focus on how to cook farmed salmon 
There are several types of restaurant that might fit your description.   I am working from a US perspective here.  Fast food - Quick counter or drive through service.  Mostly processed food in a restaurant that has a very casual ambiance.  Food is mostly served packaged and/or wrapped.  Fast casual - Often sit-down service (though can include counter service), more expensive than fast food. Can still be processed food.  Nicer ambiance, but still casual.  Family style restaurant - sit down service, where food is served to share on larger platters.  Casual dining - ambiance is still fairly casual, but nicer, less "corporate" feeling than fast casual.  Sit-down/table service and higher prices.   I guess I could also include cafes in the list...coffee shops that serve food. None of the above place a great emphasis on the aesthetics of plating food, though each has its own aesthetic. You could certainly find "quality" in each category, though there is definitely a range. 