The answer to 'why is my carpet greasy' is that your carpet may have become greasy or oily due to a buildup of dirt, skin oils, and other contaminants. This can happen over time as people walk on the carpet, leaving behind residue that sticks to the fibers. Carpets in high-traffic areas or homes with pets are especially prone to this issue.
Some common symptoms of a greasy carpet include a dull, sticky, or matted appearance, as well as a noticeable oily or dirty feel when walking on it. This can happen even if you vacuum regularly, as the vacuum may not be able to fully remove all the built-up grime.