Restaurant dress codes have always been associated with status and class; the more expensive the restaurant, the more formal, hence the dress code, right?
Things however, are beginning to change.
There is a big difference in the way people get dressed for different fine restaurants. Location can be one factor. For instance, in a 3-star establishment in Bruges - Belgium, or in many 3-star restaurants in the United States, guests are required to wear suits, even for lunch. But, in the small town of Valence - France, again in a 3-star establishment, people were dressed more casually despite the luxurious environment.
Even restaurants in the same city, enjoying the same rating have different dress code policies. For instance, Le Bristol has a formal suit requirement, whereas Pierre Gagnaire does not. Both of them are 3-star restaurants located in Paris.
Stars may also be a factor but not always. In a starless hotel restaurant in Bellagio - Como, men had to put on a jacket and if they didn’t have one on, they were given one.
If neither stars, nor location are the determining factors, then it all comes down to a restaurant's policy.
Nowadays, in a lot of places, men go with jeans or smart casual wear regardless of stars. It is probably safe to say that things are getting more relaxed in fine restaurants.
Holiday time, which is the time when a lot of people go on their culinary adventures, means relaxation time. Isn't it a dreadful thought, having to carry suits and formal wear while on vacation?