Scratching is natural and neccesary
Scratching is innate in cats and can not and should not be banned.
Cats need sharp claws to climb, play, hunt and defend themselves, which when not in use not are retracted and therefore do not wear off when walking, as in dogs. If they don't have the possibility of scratching they can grow excessively and even spike into the footpads.
Feline nail care
Scratching, cats in reality do not 'sharpen' their nails, but get rid of the old and worn cover beneath which there is a new nail. For the claws on their hind paws, they usually use the help of their teeth.
Scratching is communication
And the scratch marks (marking) also serve for cat communication, as much as visual warnings, as olfactory cues: Cats have scent glands between their footpads with which they mark their territory.
A scratching post is much more than that ...
In nature cats felines patrol their territory, hunt, climb trees, observe from above, jump, scratch ...
Cats at home without access to the outside must therefore have something where they can perform these activities without ruining our furniture. A scratching post also serves as observation platform, playground and retirement and rest area.
To find the ideal scratching post we'll do well to take into account the needs and preferences of your cat(s) before our design preferences.