The only reason why domestic cats are selectively bred is to make attractive cats which sell at the maximum price and which win cat shows because they meet the guidelines of the breed standard.
That pretty much sums it up in a single sentence. Selective breeding is essentially inbreeding to fix the genes of excellent foundation cats. Cat appearance is constantly “refined” by breeding good examples of the breed with each other, even mother with son. This is how you end up with Maine Coons with human faces and Persians with flat faces. And dubious health. Inbreeding takes place in humans as well. You can see it in the distorted faces of sons and daughters. For example, inbreeding within the UK’s Pakistani community is costing the NHS billions because they are born with inherited health issues.
The breeders tend to breed to extreme in their desire to push the limits as far as possible to make their cats outstanding in appearance. The downside which has been discussed a lot is that if there is an over focus on appearance there can be an under-appreciation of the health of the cats. Overbreeding causes health issues which take second place to appearance. This is why breeders of cats and dogs are criticised by animal welfare advocates such as PETA.
Cat breeding is all about selective breeding. If cat breeders did not do it they’d be out of business because they’d be creating random bred (mixed bred) cats which you can see anywhere on the street as strays and feral cats and which are worth up to about $40 compared to $1000 or considerably more for a nice pedigree cat. Put that way I have to return to the opening sentence: selective breeding is about making money.