Cats are often described as cute, fluffy babies armed with razor blades on their feet. That means most cats claw and scratch anything they like, which may not always be their designated scratching post.
Rather than declaw a cat, consider putting nail caps on the cat’s nails instead. This protects your furniture from scratching while letting a cat keep its claws. If stopping a cat from scratching furniture is a problem, consider nail caps as one possible solution short of giving the cat your furniture altogether.