What method of measurement would be more accurate, affordable, and practical for the tens of thousands of races around the world? There are a few methods that the cost would be prohibitive or would require dozen of workers spending weeks.
I am just returning from a site visit in Tokyo for the Olympic Marathon and had a very good meeting with the Japanese road course measurers (some of the best and most meticulous in the world). For many years they measured their races with a 50 meter tape which required many workers to create the necessary shortest path and uniform turns. How many races around the world starting with your local 5 & 10k's would be able to do this?
Our present method of measurement is "relatively accurate" for the application. Otherwise we would have very few Certified courses around the world.
Our system is one that has been tried and tested for nearly 50 years and holds up well when compared to other methods of measuring. Plus the top measurers in the world can measure a marathon course within a few meters of each other. (London Olympic measurement - within 1.5 meters of each other, Copenhagen Half - 0.30 m of each other, World Championships Doha - 1 meter).
Can we improve? certainly. Using an electric bike (which I have on several occasions) reduces the wobble, especially going up hills.
I'm good with this.