Kitchen drain lines deal with a specific combination of grease, food particles, soap, and hot water that other drains do not see. Grease enters the line as liquid, cools on the pipe walls, and hardens into a coating that traps everything else flowing through. Over time, the effective diameter of the pipe shrinks until water cannot pass fast enough.
A standard snaking can punch through the blockage temporarily, but if the grease coating stays on the walls, the line narrows again within weeks. Kitchen drain cleaning accounts for that. The work is scoped to the type of buildup kitchen lines actually produce.