Ground infiltration is the least bad thing to happen.

Keeping the water near the surface just results in more evaporation loss, and side effects for soil quality like concentration of salts.

Water infiltrating the ground will keep the soil "primed" for water absorption and storage, and prevent runoff and erosion and flash flooding. (Think about watering a potted plant with completely dried out soil.)

Plus it will just go towards recharging the water table.