It's not. The only product you could even try to make the argument for is the iPhone, but the generally-accepted categorization here is that iPhone and Android phones (and Windows phones) are part of the same category, which makes sense because people absolutely do switch between them.
Actually I have a better argument against this than my other.
No, "products from brand A" is never a category. However, a company may create a brand new market with a product, and they may be the only company with a product in that market for a while. But that still doesn't mean the category is "products by that company", it just means it's whatever new category was created from the product.
For example, the iPhone arguably created a new category of smartphones. But competitors quickly introduced their own products in this same category (e.g. Android).
I wouldn't be surprised if that's true for Apple for some of its offerings.