I’m not certain I agree with the premise that mileage is a good indicator of road wear.

I do about 30k km in a typical year. My families live far, so a return trip is around 4000 km.

If we visit our family 3x/year, we’ve effectively exhausted this “10k mile” thing (I don’t live in the UK, but the point still stands), however very little of our actual mileage would be in our home country. To be precise, only 300km out of 2000.

If I go in other directions, the math gets even worse. I can leave the country in 30km and add 800-3000km of mileage for a scuba trip.