The answer to 'why is my tile greasy' is that tile can become greasy or sticky due to a buildup of dirt, soap scum, or other residues. This can happen over time as the tile is regularly cleaned with the wrong products or not cleaned thoroughly enough.
Some common causes of greasy tile include using the wrong cleaning products (like harsh chemicals or oil-based cleaners), not rinsing the tile thoroughly after cleaning, or allowing dirt and grime to accumulate. Greasy tile can also be a sign that the tile sealant or grout needs to be reapplied.