I feel the main difference is cars can't compress time in the way an array of computers can. I could win this competition with an infinitely parallel array of random characters typed by infinite monkeys on infinite typewriters instantly since one of them would be perfectly right given infinite submissions. When I make my tweet I would pick a single monkey cus I need infinite money to feed my infinite workforce and that's more impressive clearly.
Now obviously it's more impressive as they don't have infinite compute and had finite time but the car only has one entry in each race unless we start getting into some anime ass shit with divergent timelines and one of the cars (and some lesser amount of horses) finishing instantly.
To your last point we don't know that this was cheaper since they don't disclose the cost. I would blindly guess a mechanical turk for the same cost would outperform at least today.
Considering that OpenAI's model got a higher score than any of the world's best collegiate programming teams, I'd guess that a mechanical turk would not do better (even if you gave them quite a bit of time).
In what way did the computer compress time? It completed it in 5 hours and I'm pretty sure they didn't invent a time machine
How long does a single thread take to do an attempt? How long do two threads take? I don't want to assume people reading this forum are children.
This doesn't matter. I don't intend to be rude, of course. I believe this doesn't matter at all.