Didn't watch, maybe he covered this... But something I was thinking about the other day is total square footage of rubber wear surface (not just contact patch).
For example, (4) 285/70/17 have a total of 32 square feet of rubber working on the ground in each rotation. That's a 4x8 sheet of plywood.
Now, a 35x12.50 is riding on 38 square feet (19% more rubber), with 7% more distance per rotation. So that's a total of 20% more rubber slapping per mile with the 285s. (adding a 5-tire rotation is ANOTHER +25% life)
If the wear rating and tread depth are the same, that should equate straight to tire life (but smaller tires hold more heat, so not exactly?)
Something to consider between different tire sizes... in the BFG T/A KO2 tires I bought, the 35s were MORE than an extra 20% in cost of the 285s, though, so moot point.
But it's fun to think about a 4x10 sheet of plywood covered in T/A KO tread.