Look at it this way.
When a manufacturer (or retailer) commits to offering a shoe in multiple widths, that company is making an investment towards truly serving the consumer with a proper fit. A second, third, fourth, fifth , or sixth width offering means a unique last and upper pattern cutting dye, and more, is required for each size/width combination. This is a significant expense for the manufacturer as well as the retail store willing to stock widths.
Width sizing represents the highest standard of footwear, and it is generally found at the top US manufacturers, Alden and Allen Edmonds.
The concept of proper fit was born decades ago when US manufactuers and retailers worked together to offer consumers a correct fit. At that time it was common for each large city to have several retailers stock walls filled with one shoe, that shoe coming in AA, B, C, D, EE, EEE widths.
And there were several US manufactuers producing those widths.
But now the shoe industry has changed. By the late 70's US manufactuers were giving way to cheaper imports, and US consumers developed a taste for lower cost disposable footwear. Instead of one shoe offered in multiple widths retailers filled their stock room shelves with six different shoe styles , each only offered in medium width. The concept of true fitting was replaced by large selections of imported single width flashy fashion styles.
So, the US shoe industry, both on the manufacturing and retailing side, with the exception of Alden and AE, has sold out substance (proper fit) in favor of imported single width fashion styles. The UK manufacturers were always, and continue to be about their own style (nice leathers, finishing details etc...) rather than substance.
Huh?
Shoes that fit well are important, but have nothing to do with the quality of manufacture. The lack of different widths in the UK shoes has nothing to do with whatever brand integrity is supposed to mean. To me, brand integrity means making an honest shoe as well as you can for what you charge. In that regard, many UK shoes are superior to anything made in the U.S.
Until quite recently, the U.S. and UK shoe markets were entirely different. The U.S. RTW industry for both shoes and clothing has always had a much wider range of sizing available compared to the UK. In that sense it has been superior. But that's about it.
I wear a size 11D in U.S. shoes and 10 in UK shoes. And the UK shoes fit me better. But anything short of bespoke is not going to offer me or you proper fit, it is all going to be a compromise. My feet are more than a 1/2 size different. I split the difference. The left shoe will just fit, the right will be a little long. I have an average to slightly above average width across the metatarsals, but a moderately narrow heel. Both Alden and AE make a lowest (Actually highest) common denominator broad heel. I.e., a heel that will fit the widest heel likely encountered in a given width. Most UK makers have lasts with a narrower heel. They will tend to fit me better. Does that indicate greater integrity? Not necessarily, it's just a different, but better practice.