The answer to 'why is my floor grimy' is that there are several common causes, including not cleaning the floor frequently enough, using the wrong cleaning products, or having a buildup of dirt and grime over time. Floors can become grimy for a variety of reasons, such as high foot traffic, pets, or spills that aren't cleaned up right away.
To address a grimy floor, you can try sweeping, mopping, and using the appropriate floor cleaner for your floor type. If the grease and grime are stubborn, you may need to scrub the floor with a stiff-bristled brush and a stronger cleaning solution. If the floor is still looking dull or discolored after cleaning, it may be time to refinish or replace the flooring.