The car gets 520 miles of range.Ummm, what?
So I buy an EV. Then over time it loses efficiency. One possibility is that it's less efficient at charging. That would mean it costs me 10% more in electricity, which may or may not translate to dollars and/or time charging. Another possibility is that it loses 10% of its efficiency on the road. In that case it loses 10% of its range.
You may hold that it's arguable which situation is worse, but in no way does it amount to the same thing. I much prefer the former.
It “costs” 134kWh at the charger to get that range.
Why it takes 134 kWh doesn’t make a difference, that is the energy consumed to get from point A to point B.
I’m not sure how any of this relates to efficiency loss over time.