Exactly. They have revenue in the low 6 figures per vehicle annually, so they probably need to get the number of operational employees per vehicle down to around 1/10. Seems feasible, but they're probably not anywhere close to that yet.
On the other hand, HN has consistently underestimated them for the last two years or so as they've begun to commercialize. Their trajectory has been 10x growth in rides served per year for a while now. At the current scale it's hard to imagine they could grow another 10x in the next year without being close to break even on operating cost.
10x growth would be ~$1B revenue, 7000 cars. Let's assume it requires doubling head count from 2500 to 5000. That's $130K/car, $250K/employee. sounds break-even-ish.