Red telephone boxes are only found near tourist attractions as tourists like to be photographed using them. Nobody uses them in real life any more.
By avoiding red telephone boxes we avoid tourist mush.
On the other hand It is nearly always cheaper to go to a non branded outlet for lunch if you are in an area where the same people are to be found each day- such as your place of work.
This is because it makes no sense for the owner to alienate you. Word gets around quickly in an office and the company would rapidly fail.
The same is not true in an area where different people are to be found each day- such as tourist attractions. Here you are better off going to a chain. It matters little to an independent operator if he alienates you a tourist that will never return in any event.
The same is not true of the chain. You may not visit a particular location again but the chain must consider their brand. If they upset you in one location they lose sales in every outlet across the country.