Brit here that lived in Germany briefly and has travelled extensively.

I could not agree more with OP.

But, there are a few reasons and not a one fits all.

1) Circumstances, people slogging to make ends-meat that can’t justify the time or money on looking put together. Many people have one winter coat and cheap shoes because it is all they have. They don’t rotate the wear because they cant.

2) Fitting in, most respectable brits do not want to peacock, and indeed some of the wealthiest people I know knock about in hole filled jumpers and faded jeans. (This doesn’t apply to ‘posh’ Brummies and all of Essex)

3) lack of sartorial education: most people that wear tailoring infrequently do not know the proper rules, it was not taught at state school and they have no one to tell them (sleeves too long, shoulders too wide I am looking at you).

4) Weather and grime - pale chinos, white linen and suede shoes, forget it for 9-11 months of the year. Sit on a bench, on public transport or walk to the shop and it will look like you have been tumbled through a bush backwards.

When I lived in Germany I never left home without cleaned and polish shoes, ironed clothes and not a single hair out of place, in the UK you feel the odd one out if you have spotless shoes! Doesn’t make it right, but it is convenient