20 GBP for lunch? Even at 10 USD I'll buy lunch only once in two weeks. A 20 USD lunch is a rare treat for special occasions only.

Surely it depends on the income level? There are people for which a $20 USD lunch everyday or close, is nothing to write home about.

In fact their time can be far more valuable (into what money they can command by doing some extra work), so that the opportunity cost between cooking and buying lunch to make it not worth to cook.

I'm just pointing out that the demand for eating out is highly elastic. If the restaurant industry as a whole raises prices relative to background inflation, then overall sales will fall and some will go out of business.

The probability of the food from a restaurant being sufficiently tasty/nutritious is way too low compared to the effort required to make it at home for it to be worth spending 20GBP eating out all the time.

I also simply choose to eat out a maximum of 1 or 2 times a month. I can afford 20GBP, I just have better options.

That's pretty much the prices in Norway. To be fair Norwegians do eat out less than in other places as a result of it.

That’s about 15 minutes of labour for a software developer. So less time than you’d spend eating it.

Like with everything, all that matters is whales. The kind of person who eats lunch out every day doesn't care if it's 20 GBP or whatever, so they'll keep paying whatever it costs to eat whatever they want. What'll happen is places without enough whales, like low foot traffic, will poop out or become ghost kitchens.

No, you're not. But I guess it depends on what you call "restaurant" and "lunch out". Some people will basically eat every working day in a restaurant. So more than £/$/€10 will be seen as expensive. Some people, like me, will go to[1] a restaurant once or twice a month. In this case, £/$/€50 will be totally acceptable. And giving what is sold in places where you eat for £/$/€10, they will avoid going to those places in the first place.

So I guess restaurants that sells food are having a hard time, but restaurants that sells a service have a different story to tell.

[1] See how in the first case it's "to eat in a restaurant" and in the second it's "to go to a restaurant". To me that's the big difference : when you are here to fulfill a natural need (eating), you don't want to pay a lot for it, while you are here to have a nice time out, you will gladly pay more.

I spend maybe 40€ per week on food, not just lunch. 20 pounds for a single meal seems a bit expensive to me.