I understand your pain completely. Most of my cats over the years have had a go at the carpets to varying degrees, but Toby takes it to a whole new level and we've had to resign ourselves to fluffy carpets. He does it when he's excited, when he wants attention, when he's hungry, when he can’t open a door, and, most bizarrely, whenever we put something new on the floor (eg a bag of shopping, a bit of newspaper on the floor when drying wet shoes, anything really). In the latter case it's partly excitement and partly scent marking (cats have scent pads in their paws). Ignoring him when he does it makes no difference, because frankly he is a complete nutcase, and normal rules don't apply. It might work with some cats, with a LOT of persistence and consistency, but given that Toby does it even when we're not here (we find the fluffy patches round things on the floor when we get home), it's unlikely to work with this little horror.
We have learnt a few things that help though:
1. Keep a plant squirter to hand, and when he's actually scratching, give him a verbal warning in a very stern voice (so he learns to associate what's about to happen with your tone of voice), and if that doesn't work, give him a quick squirt. Very quickly all you'll need to do is actually shake the plant squirter, and they stop. But this does mean that you'll have to have plant squirters readily to hand. Sometimes just the stern voice is enough to stop him now though.
2. On the same psychology, I also have a loud squeaky toy by my desk in the spare room, and when he starts scratching to get my attention I give it a few squeaks and that usually stops him in the moment.
3. Put double sided sticky tape (eg "Sticky Paws") in the areas that he favours scratching. It may just redirect him to somewhere else, but it will at least spread the load and will stop some spots (usually by doors or in corners) from becoming threadbare. You may find you can take them off eventually and he won't return to that spot as the habit has been broken and/or he associates the spot with the sticky experience.
https://www.amazon.co.uk/Sticky-Paws-29 ... 452&sr=8-8
4. Put a scratching post in the spots he favours most. You may end up with loads of them (we have four) but it does seem to have done the trick for those parts of the house, and he has finally learnt to use the scratchers in those spots.... although sometimes he just scratches the carpet around the post ...
so we put a carpet offcut under the scratching post, which he can wreck to his heart's content
5. You can get citrus based sprays (from pet shops) that may stop him from using particular spots, although we tend not to use them as I would need to top it up so frequently I'm not sure whether it would eventually stain the carpet
6. We have one of these to get the fluff off the carpet and return the knap - it's an absolute godsend. We just go round prior to vacuuming and give the carpet a quick brush down with this in the direction of the knap, and it makes a huge difference
https://www.amazon.co.uk/Glosstock-Ltd- ... 436&sr=8-6
But the main thing, which I think you've realised, is to listen to him and try to respond. He's not doing it for the fun of wrecking the carpet, he's trying to tell you something. A contented cat is much less likely to be destructive so we work to fulfill Toby's needs, which is actually very rewarding as it makes us interact with him and play with him more. And let's face it, it's much more fun than working or surfing the internet.
Your puss wants your attention for a reason, be it affection, shared play time (most cats much prefer to play with us than to play on their own), hunger, wanting to be let out, etc. While some dislike cats for being aloof, we should feel blessed when we have one that is a communicator, and that wants to interact with us. With Toby, despite his destructive method of communication, he is a really funny character and very sweet natured. It's like having a demented two year old in the house sometimes, but despite his hyperactivity he constantly makes us laugh. He's not a lap cat but loves attention and interaction, so instead of focussing on his faults, we adapt to his personality and try to accommodate it. It's been a slow learning curve for both parties, but he is learning that there are other ways of getting through to us, and we are learning to understand what he's trying to tell us before he destroys the house!
I hope this helps.