If you have slop in your rudder system you can't maintain a proper toe adjustment. I doesn't take much, a little here and there and it adds up. You might set your toe-in at 3/16s but with all the slop out on the water your rudders might be toeing out. Slow.

A race car achieves top speed in a straight line. The second the steering wheel is turned just a little the car slows. While sailing if your rudders are down there moving all around they're using energy, slowing you down.

A tight system will wear less and will be more enjoyable to use.

Have Fun
Mike