I wanted to see if I could wear the tire down until I can see the air, but that would probably be a bad idea and cause an UPD.
And a popped tube.
I wore my rubber out. Insert YOUR joke here…
Ride it, don’t slide it? 
Anyway, looks like you came pretty darn close to seeing air there…
It doesn’t look two tired.
Baldness is no laughing matter!
Time to learn to idle with your right foot.
It’s now lighter weight and more aerodynamic!!
Considering the weight of the tread on a 26" Duro, I really wouldn’t be surprised if it’s about 500g lighter than a new one at this point!
“We’ll set aside a little time to fix a flat or two,
My tires and tubes are doin’ fine but the air is showing through.”
(Who recognises that without cheating with Google?)
It’s better to have skid marks on your tire than your underwear
It only looks bad on that one side.
Looks like Mrfixit’s tire could have benefited from being rotated when it started to show wear in one area.
Here is a past thread on the advantages of rotating tires and/or cranks to even out tire wear:
Time to get a day job.
That’s what it looks like after rotating it about 5 Times.