That is definitely not true for the places I am familiar with on that list.
A few examples: French Laundry, Alinea, LeBernadin, Joël Robuchon ....
They are on the list for a reason
Well, it
was a generalisation. It isn't inevitable but it does happen and when the rot does set in it isn't always immediate.
Many years ago we used to spend a few days in Paris every year. When there we always frequented a small, family run restaurant as most restaurants in France were then. It was very popular with the locals but not much used by tourists. It was very basic, with a set menu of seasonal and beautifully cooked and presented food and very friendly and everyone sat at a long table and helped each other to food and wine (it would be quite trendy theses days. The staff were efficient and helpful and cared both about their jobs and about their customers and the food was out of this world.
And then one of the Sunday newspapers devoted their colour supplement to Paris - its museums, art galleries, shops, "the sights", the parks and the restaurants.
One of the restaurants it featured was "our" place. Photographs, write-ups about the food, interviews with the patron and customers, the whole nine yards.
About 8 months later we made our annual excursion to Paris and went to "our" restaurant for dinner on the first night. It was awful. The place was full of Brits complaining (and with good cause) and there were none of the old local clientele in evidence. It was scruffy, the staff run off their feet, slap-dash and rude, and the food was badly cooked and badly served and in any case comprised of poor quality ingredients and talk about expensive!
When we got back to our hotel and mentioned it to the desk clerk she said that if she had know where we were going she would have warned us off. The locals no longer used the restaurant because of its decline and she even knew of the article in the colour supplement and dated the decline from that.
It is a sad fact of life that some places get too full of themselves and begin to think they are more important than their customers and there has been more than one "top chef" in my own country who has found himself in a financial mess with a failed restaurant because he forgot where his income came from and who actually paid the bills.