Yeah, I mean its one thing to take a seat in a rocketship and go along for the ride, but its quite another from a challenge and career perspective to turn the rocket thats falling to earth around and pointing it in the right direction.
Generally at this stage in my career, I would probably enjoy the latter more. I was a smallish part of two turnarounds like this, and its just a real joy watching people get unshackled. Just stripping away busy work like requiring accounts to get approvals by 3 people (and why not just give everyone in the tech org a gitlab/pagerduty/whatever account and write a script that if they don't use it for a month, its automatically deactivated). Just asking why repeatedly until you finally get to the "scary" person no one wanted to confront who can't give you a good answer so you just say ok, lets just get rid of this... Removing the busy work, getting rid of bureaucracy, which I hear exists in enormous amounts at GM and other automakers... yeah taking that and just turning everything on its head can be wonderfully rewarding.
I would take a job like that again in a heartbeat. And tbh, he is a big enough deal at this point its not like its going to be career ending if he fails. And if he does fail, its likely just going to be from not being given enough authority to make the changes he wants. One kind of argument that may be very difficult to swallow for his upper management- allowing fully remote workers/teams. I am sure there are a lot of people that will want to work on something like this, but not a lot of them are going to want to move to Detroit to do so. So then you pivot to "well are you open to opening an office in the Bay area" and they reply "well that sounds expensive!" and you say... well we can also do it cheap and hire remotely, maybe even save on salaries... and then you get the "but what about [how do we know if they are working|Corporate Culture|That sounds scary" and on and on it goes until someone blinks. Anyway, getting into the weeds, but this is just a small facet of what goes into a role like this, before even getting into anything technical.