Things might not work itself out in desirable ways. I imagine what will happen is that portions will shrink, and become adulterated. For example, a restaurant ostensibly using ground beef might partially substitute something cheaper... Food fraud is rampant in developing countries. One example:
https://www.foodnavigator.com/Article/2025/07/28/food-fraud-...
https://scijournals.onlinelibrary.wiley.com/doi/10.1002/jsfa...
Well if you care about portion size or the introduction of substitutes then you can change your buying habits. We only eat out for dinner at great restaurants because I can cook better food at home in a lot of cases.
You're going to have to change those habits anyway because even without inflation that has been ongoing since the pandemic began you still have a lot of pressure to push prices higher on beef and other "luxury" goods as global demand continues to increase, the environment becomes worse off and requires further regulation, &c. It's perhaps a head start, but the long term trend isn't toward lower prices regardless of the impact of inflation (for example).
> We only eat out for dinner at great restaurants because I can cook better food at home in a lot of cases.
I also rarely eat in a restaurant, but when I do I make it a great one (to me -- I'm not talking only or even mostly about highfalutin places). Aside from being a better inherent experience, it also makes it more of a special event, which increases the pleasure I get from it. Any fantastic thing experienced frequently ceases to feel fantastic.
The truth is that most people can cook better (and healthier) food than most restaurants. The value proposition restaurants provide is mostly experience (a lovely night out in a pleasant environment where you're being waited on is fun) and convenience (just because you could cook it better doesn't mean you want to, particularly for lengthy and involved dishes).
> I imagine what will happen is that portions will shrink
I wouldn't mind this up to a point. One of the things that I find really irritating about most US restaurants (I'm an American, if it matters) is that the portion sizes tend to be far too large.