My Moonlander fat bike is regularly getting rear tire flats. Turns out I'm at about the same tire mileage where it started doing it last time. The low pressure flexing of the tire causes the rubber to flake off exposing the casing fibers which rub against the tube wearing holes. I added sealant which worked for a while, but I don't think the sealant can easily get to the part of the tube with the holes. Tons of tread left by the sidewalls are toast, but I suppose 10,000 km isn't bad for a tire.

Both Tires were Surly Lou. And both had serious rubber flaking issues, not sure if its a bad compound or poor vulcanization. A 45Nrth tire I have on the front doesn't have the same problem, so I ordered a 45Nrth Wrathlorde instead of another Lou. That will save me some effort as it is a pre-studded tire and I won't have to screw in 200+ grip studs. I sure got my moneys worth out of those grip studs. I first had them screwed into a Surly Nate on my Pugsley, then moved them to a Surly Lou after I switched to a Moonlander, then moved them to the second Lou tire. All told over 20,000 km of use on those studs and they are still in excellent condition.