Cats are not plush toys. They are living creatures. They can be lovely companions, but they will barf on your carpet, annoy you with making noise when you are trying to sleep and possibly destroy you furniture. If your possessions are more important to you than wellbeing of your pet, do not get an animal.
"But people dock dogs' ears and tails for aesthetic purposes and that's fine!" No, it is not fine. It is painful, cruel, and unnecessary, but at least it is not crippling. Declawing removes the last digit of cat's toes. Cats walk on their toes. Do you see the problem here? Even if they recover from this butchery without complications, they can have future problems with mobility because of how they have to adjust their stride. The tips of the paws are also more sensitive, with may interfere with things like digging in the cat litter.
"I knew/had a cat that was declawed and he was loved and spoiled and healthy and fine!" I am delighted that that cat has adjusted to its maiming and had a nice life. (BTW, you can have no idea about things like pain it was in, because cats are excellent at hiding illness.) This is not a reason for you to do horrible things to another animal and think that it will turn out right.
"It is better for cat to be declawed and have a home than not to have one!" Think about it this way: it is better for the cat to be maimed and have a home than to to have one. Does not have quite the same ring, does it?
I do not care what you tell yourself to make you feel better: if you declaw your cat or you are a vet performing declawing procedures, you are a bad person and cannot consider yourself and animal lover.