The London market is well established, so "you have a huge number of people who are willing to invest", he said. "If you have a good idea, you can see a route all the way from pop-up to private-equity sellout. Previous generations didn't really have that."
According to the 2016 edition of the guide, published on Thursday and based on a survey of 6,750 diners, 179 restaurants have opened this year, above last year's 148 and the pre crisis peak of 158 in 2008. The number of closures rose slightly, from 47 to 56, but the ratio of openings to closures was the second-highest for 25 years.
As last year, The Wolseley, The Delaunay and The Square were judged the best restaurants for doing business. In the Square Mile, the best choices were City Social, Galvin La Chapelle and L'Anima.
Previous guides pointed to a lack of top-notch eateries in Canary Wharf and this situation persists. "It takes time for a restaurant ecosystem to establish itself," said Mr Harden. The abundance of bankers was not necessarily conducive to haute cuisine, he added. While "eating out in the Wharf has made tremendous strides in the past few years . . . when you have a captive market, [restaurants] don't have to try that hard."
The same is true of the Square Mile, he said — "dining out in the City has always been famously not as good as in the West End".
When it came to "top gastronomic experience", Michel Roux's Le Gavroche was voted number 1, displacing The Ledbury in Notting Hill.
Several big names appear in the ranking of most overpriced restaurants, with River Café holding the top spot for a second year. The Italian establishment in Hammersmith, where a main of baked salmon with salsa verde and verdura mista is £40, was described by one diner quoted in the guide as "eye-wateringly expensive, but brilliant" and by another as "insane for a bit of al-dente pasta".
The food at the Chiltern Firehouse in Marylebone was judged by the guide's panel of reviewers to be "most disappointing", with one saying the celebrity hotspot was frequented by "Z-listers". However, there are other factors to attract customers: in its price bracket, Chiltern Firehouse was rated in the bottom 10 per cent of places for food but in the top 30 per cent for atmosphere.
However, one diner's haute cuisine can be another's overhyped disappointment: three restaurants made it into the top10 lists both for "top gastronomic experience" and "most overpriced" — Dinner by Heston Blumenthal, Restaurant Gordon Ramsay, and Pollen Street Social.
"It doesn't matter how good a restaurant you are there will always be some people who are disappointed, and no matter how bad you are, there will always be some who are delighted," said Mr Harden. "How good a restaurant you are depends on the balance."
The guide's ratings were determined using the views submitted in 60,000 reports.