As for dress shoes being hideously uncomfortable, that's really a matter of fit and quality. For years, I walked several miles per day in NYC in leather-soled dress shoes and they were perfectly comfortable. Now I kinda' regret that I wear a pair of running shoes to my tech job and all my nice dress shoes are gathering dust in my closet.

As the old saying goes "no brown in town"....

It's an old UK social class signalling thing.

Only really applies to particularly stuffy organisations these days - but the do exist in the finance/legal worlds.