Is time dilation essential to GPS? I know the satellites' clocks have to compensate for time dilation, but that's not the same thing. Or am I too simplistic? I

Is time dilation essential to GPS? I know the satellites' clocks have to compensate for time dilation, but that's not the same thing. Or am I too simplistic? I just figured that, if the engineers who built the GPS hadn't accounted for time dilation, we'd just see the error range on GPS expand, and would have to resynchronize the clocks every once in a while.