Absolutely agree it's about your 'tribe'
I moved from the area where I was a student, for a job where I wore a suit and heels every day. (Long time ago)
I completely thought that "everyone" was just so much nicer, kinder and much keener to please. As a student I had often not been treated well, as a business person I was given attention and, goodness, yes, respect.
However, people serving in really good shops are trained to evaluating people more closely, looking for example at their shoes, in order to not alienate someone who might otherwise turn into a good customer.
No 'clues' are really reliable, because they can all, with knowledge and effort, be faked and the fact that you know what to fake can be a clue in itself.
Amongst my friends, I too take account of shoes. I can be pretty sure that anyone wearing high heels will not turn out to be a kindred spirit.
Oddly enough, then, the people who turn into real, true friends, are often those whose shoes, and general outlook on life, are not the same as mine.
If they turn out to be friends in spite of such big differences, the friendship will be a good 'un.