I think you missed that the whole point of this race was:
"did we build a vehicle faster than a horse, yes/no?"
Which matters a lot when horses are the fastest land vehicle available. (We're so used to thinking of horses as a quaint and slow mean of transport that maybe we don't realize that for millennia they've been the fastest possible way to get from one place to another.)
> "did we build a vehicle faster than a horse, yes/no?"
Yeah fair. There's also that famous human vs horse race that happens every few years. So far humans keep winning (because it's long distance)