I would agree with you, it is an awful thing to do, I once looked into what they actually do to de-claw a cat, there are several different methods, but basically the make an incision into the bone…yikes!

You can however get their claws capped, I think this is just putting little cases over the tips of the claws so they are not so sharp, or just trimming the claws (you can do this yourself or get it done at the vet). I never do anything with my cats claws, but I think as my cats go outside, they get blunted by climbing trees and walking on concrete.
I do however trim my mums rabbits nails, and if you can keep them still, its pretty easy, so I should imagine it’s the same for a cat.