There is a bullish take on zach going. It might well be wishful thinking, but the logic is sound.
The CFO position is probably very exciting for a company that needs a major financial turnaround (like Rivian), and taking a company thats in the red and turning it to green is probably a real feel-good thing for a CFO. It doesn't sound like blowing up the death-star or defeating voldemort, but for someone who is a CFO, thats probably the best metaphor.
Whats the challenge for zach now?
The company is printing money like crazy, has zero debt, has enough cash to finance all foreseen expansion, despite a crazy rate of growth, has decent profit margins.... how tedious. Frankly from this point on, the job sounds kinda dull. Dojo needs a big investment? here, take some of this massive pile of cash. Supercharger network needs expanding? have some more cash.