Tie rods and ball joints are essentials of the suspension system. If you ask what is the 'benefit' of putting new ones, Id just simply say that one fine day it may save your life. And that is an understatement.
Tie rods help turn the wheels up front. They are also 'ball joints' like your shoulder and hip joints are allowing for some movement while enabling wheels to turn. Worst case scenario, badly worn tie rods can pop out and make one lose control over the vehicle. The two front wheels can turn according to their own will.
Putting in new tie rods are good for maintenance of the suspension. The steering will have lesser play and would feel soft. VW Bugs have two types of tie rod ends......the change happened during the 68 year model so some 68s have the earlier, while some 68s have the later kind. Earlier has a thinner dia and accepts a 17mm nut. Later are thicker, accepting 19mm nuts. You of course need the earlier variety.
Similarly, ball joints are also essential maintenance. Safety hazard when worn, if it pops loose, the wheel may 'fall off' partially, but enough to cause an accident.
Both tie rod ends and ball joints must be put brand new. There are people who advocate 'repairing' these but it is not at all recommended. They are dangerous and make the steering harder to turn, straining and wearing other components like your steering box prematurely.
From the posted pics, I can see that the ball joints are *severely* worn and have been repaired in the past.....there are tell tale marks of hammering, spot welding and what not. These MUST be replaced asap. Hope they were not re-repaired?
Also, both tie rod ends and ball joints must have good quality boots with good quality grease filled to protect them.