Quite the opposite. Value is essentially a function of scarcity relative to desire. Food desire may be, for all intents and purposes, stable, but availability is most certainly not. Something like a major weather event wiping out a crop can quickly change the scarcity profile. Food is especially prone to value variances over time.
What specific definition of value are you using here? Sometimes terms with value get into the same realm as price, but the default definition of value is the benefit you're getting, and going to similar restaurants ten years apart is damn near the same benefit. Scarcity doesn't come into play.
Also, desire for restaurant service is driven by people with disposable income looking to treat themselves much more than baseline food prices. Restaurants serving this demand can optimise prices for their limited capacity, and have staff and real estate costs to consider