Concrete sealing is indeed necessary for several reasons. It provides protection against water, oil, stains, and contaminants, extending the concrete's lifespan. The sealing enhances the concrete's durability, making it less prone to cracking, chipping, and abrasion. Aesthetically, it improves the appearance with a glossy or matte finish and enhances color vibrancy. Furthermore, sealing saves costs in the long run, as it reduces the need for frequent maintenance and repairs.