There is no supposed to and carpeting cannot be replaced with a tenant in it. The place would have to be empty in order to install new carpeting. Obviously, you are living there so the landlord cannot do it now. Such a thing is done BETWEEN tenants. And, every 10 years is complete BS. It is done when the landlord decides it should be done. How a carpet wears depends on its quality. A good wool carpet can still look great after 25 years. Some cheap carpets can look like crap after a couple of years. You have no right to expect new carpeting. It won't happen. If you want it, the landlord might allow you to do it but, it would be at your expense. He might be willing to kick in some money toward it but if you are not prepared to move all of your belongings out while it is being installed, which it would have to be done professionally, then it won't happen.
Certified Paralegal, with 25+ years' experience & with Landlord & Tenant law experience.