I work in the retail industry and just wanted to dispel some of the myths here.
Leather is what is referred to as a co-product of the meat industry, because both are valuable. However, it's not a UK industry. The vast majority of leather in UK shoes and furniture comes from South America, where they are cutting down huge swathes of the rainforest to farm animals and crops. Animal welfare is not high on their agenda.
Fur farms are truly horrible. Far worse than battery hens or pig stalls. So even if it's 'ethically' sourced, it's not nice. Much of the fur that is sold in the UK as trim comes from China. There, they take dogs from the street and skin them alive. Google it. If you can stomach it. That's why most of our high street brands ban fur entirely.
The dairy industry is pretty cruel too. As a general rule, cows are either bread for meat or dairy. If a male calf is born to a dairy cow, it is shot. It has no value. There are some farmers who are breeding cows that can be used for both meat and dairy, but they are rare.
Similarly with chickens, they are bred for either food or laying. If male chicks are born to a laying hen, they are usually gassed or they go into a mascerator. The mascerator is a long tube with lots of blades in it that chops them up. Sometimes they are gassed first, sometimes not.
Abattoirs are pretty horrendous too. The animals smell blood, they can be distressed. We monitor various indicators to show if the animal was distressed when they died. These have to be evident in less than, say, 5% of the sample. But they don't have to be absent.
I'm a vegetarian but not a vegan, so some of this I'm indirectly responsible for. I'd never wear fur. Why, when there are alternatives available? I think my point is that unless you live a very 'ethical' lifestyle we're all responsible for animals suffering in one way or another.