'So why not buy from charity shops, ebay, use freecycle etc exclusively? '
Because I live in a remote area and there are two charity shops in nearest 'town' which is about 14 miles away from here. By car - the bus stop is 3.5 miles from here and it costs £2.10 each way for the ride into town.
And I have yet to see anything worth buying in those shops, unfortunately.
I got burned BIG style by Ebay - twice, once by a buyer and once by a seller, so I don't use it anymore.
As for freecycle, once again, we'd have to drive around. It's anything but cheap.
There's a boot sale on tomorrow in a village, so we'll try there.
But once again, I reiterate, that when you live in a rural location and you come into town once a month to do a big shop - and the only shop is Tesco's and you're not well off or you have transport issues - chances are, this is where you'll buy clothes.
I don't use supermarkets except for now and again for staples myself, but for about 95% of the people who live out here, that's where they go because that's pretty much all that's on offer, particularly if you have no internet, which a lot of the elderly around here do not.