Welcome to the discussion.
I find no merit in this valuation-per-mile-driven metric. Let me give you a hypothetical: a small pharma company, with no approved products currently being sold, receives FDA approval for a new drug that, in a single dose, cures any known cancer. Would it be reasonable to value this company on a valuation-per-doses-sold metric? It will look vastly overvalued compared to, say, Merck, which has sold billions upon billions of doses, but any rational investor will realize that this new company is poised to earn untold billions in the future.
The "per miles" metric is not merely backwards-looking, it's about cumulative backwards history. Of course there have been more miles driven in Fords than Teslas, but that doesn't tell us anything about their value today. Heavens, there were probably more miles driven in Edsels, and we know what that company is worth today.
Stock valuation is inherently about the future, not the past.