A similar but not quite the same mechanic is fuel economy.
Let's say you have two vehicles, both doing 10,000 miles per year. One gets 10 mpg and the other 50.
Would you rather upgrade the 10 mpg vehicle to 13 mpg, or the 50 mpg to 100 mpg?
Not only should you pick the former - you should pick the former even if you could upgrade the 50 mpg vehicle to run on nothing.