The answer to 'why is my countertop grimy' is that countertops can become grimy over time due to a buildup of dirt, grease, and other residues from daily use and cleaning. This can make the surface appear dull, discolored, and unclean. Common causes include not cleaning the countertop thoroughly, using the wrong cleaning products, or not sealing the surface properly.
To address a grimy countertop, you should first try a thorough cleaning using a mild detergent or specialized countertop cleaner. If that doesn't work, you may need to use a stronger cleaning solution or consider resurfacing the countertop. In some cases, it's best to call a professional cleaning service to deep clean or refinish the countertop for a lasting solution.