What is wrong with this tire?

Try keeping the 5th wheel well greased. Believe it or not lack of grease can cause about that same wear pattern on steer tires

 

kingpin, wrong aligment, bent frame, broken leafspring.....

 

Alignment out of speck when all else is good usually gives more of an even accelerated wear.
This point to some sort of mechanical issue like mentioned by the other posters.
I must add loose wheel bearing as a possibility.

 

need alignment.

 

When the same wear pattern is on inside or outside of both tires and you can feel sharpness on the edges running your hand across the tread face then it's a toe in problem.

 

I'll be remembering this for sure!

 

You drive too fast and have too much pressure in the tire.

jus my 2 cents.