The diner is on a phone, hungry, and deciding in seconds
Picture the real visit: someone is standing on a London street or sitting on the sofa, on their phone, deciding where to eat in the next hour or for Friday night. They want four things fast — what kind of food, roughly the price, can I book, and where are you. If your site makes them hunt for any of those, they bounce to the next result before your hero video has finished loading.
This is the mistake most restaurant sites make: they are designed to look impressive on a designer's desktop, not to answer a hungry diner's questions on a phone in ten seconds. A great London restaurant website is built mobile-first around that exact moment of decision, with the essentials — cuisine, vibe, menu, booking, location — reachable instantly, not buried under an intro animation.