AV Companies: Why the budget / team size difference?

Kinda business-y / economics question here…

So according to this video, in the DARPA Grand challenge some teams had a budget of $3M and ended up building AVs that made it through a challenging, 100+ mile course fully autonomously.

Now, compared to that, for something like an airport baggage tractor, or even those AVs being piloted in shipping ports, it looks like the startups can struggle with cost overruns in excess of $10M+ with HUGE teams. How is that possible? Aren’t these vehicles just following pre-planned lanes / routes?

While I get how there’s a complexity factor to reach commercial-grade safety in the real world, shouldn’t the engineering requirements for closed environments here (vs the general AV case) be significantly simpler? No shade intended for any of these companies, but like why can’t someone get by with say $2M and a ~5 person team of smart cookies?

People. The grand challenge needed to navigate static terrain. An airport has people wandering around, other vehicles to yield to, it absolutely can’t cause a plane to burst into flames and kill 200 people. There could be another baggage tractor in the way. Is it allowed to leave the ‘safe’ path and go around or will it hit a fuel line?

Ultimately the Mojave desert was just a closed course, albeit a very large one. Except for Stanley overtaking a car on the open flats the vehicles didn’t need to interact with any adversaries that it needed to interact with. An airport is still an open environment with people on foot, people in carts, people in cars, people in busses, people in airplanes, people hauling hoses etc.

And once the cart arrives at the airplane, you still need someone to manually move the luggage off of the tractor onto the conveyor belt. So you need at least one person on the tractor anyway for most of the trips to then unload the vehicle.