That just looks like the typical 'lack of effort' in riding mower tie rod ends. Well, maybe a little better than average, but still. I always compare an open/unsealed spherical joint like that to a mortar and pestle. Great if you are trying to grind up spices, or spicy dirt in your yard i guess?
Anything that's not sealed up with a grease boot (and grease in it) is just going to wear quickly. Sometimes it doesn't matter (ball ends on 3pt, nobody really cares) but on the steering you constantly interact with the slop it creates.
There are lots of threads all over about upgrading tie rods on riding mowers, garden tractors etc. My preferred parts donor (although it does require welding) is automotive swaybar endlinks. They are sealed, greased, and often greasable, basically the same thing as cars and larger tractors have as steering tie rods, only smaller.
I actually have a couple of these things (cut and welded for length/orientation) serving as the side links on the 3pt of my little Case garden tractor too.
If you were to replace your tie rod ends again with the same style of part you already have, I would just try to create a 'boot' to keep dust out of it, and drip some oil onto it every once in a while.