The answer to 'why is my countertop greasy' is that a greasy countertop is usually caused by a buildup of cooking oils, grease, and other food residues. This can happen over time from regular use of the kitchen, especially if the countertop is not cleaned properly or frequently enough.
Some common symptoms of a greasy countertop include a shiny, slick surface, a noticeable oily or sticky feel, and the ability to leave fingerprints or smudges. This can make the countertop appear dirty and unsanitary, even after cleaning.