I think the point that many are glossing over in their anecdata is that those cars they got 100k+ miles on where likely a decade old. The Model S in question is probably under 3-4yrs old, likely much less. 70k miles isn't much, yes, that's true. 70k miles in 1-2 years is however a very different scenario than 70k miles in 4-5 years.
How do you see the timeframe effecting wear and tear on a car? (In a general situation, I mean; not necessarily down a dirt road every day.)
Take 2 cars. They each drove 70k miles; car A took 1 year, car B took 4 years.
It seems to me that car A will have less wear and tear simply because it's much more likely they were putting highway miles on their car. Aren't highway miles easier on all the components?