Your line "Sure — if I fail, I’ll just use that position as a stepping stone to my next executive role" indicated a certain cynicism in your own post, so I was reflecting that in my response.
So here's the more detailed sincere response, based on experience working in a similar large, similarly dysfunctional technology company (and also knowing people who spent several years at Boeing specifically):
It is usually not possible for a chief executive to fix a company. The reason is simply sheer complexity. A company of 100,000 people has potentially 100,000! (factorial) different working relationships within it. In practice it's less because not everyone communicates with everybody else, but even a small department of 100 people has more different relationships than anyone can possibly keep track of. No one executive is going to know every single employee, every team, every project. And without them having those personal relationships, they don't have enough trust to convince people to alter their behavior.
If the company is in trouble in the first place, that means that the way they do business is no longer adapted to the marketplace. So you need to get the company to make changes. But if you root cause each individual problem, you find that the company is fractally fucked up. The employee is usually acting according to the incentives available to them; if they did things differently, they would fail to get the cooperation needed to accomplish their goals (at best) or lose their job (at worse). And that's the key part: in a big company, achieving any goal, regardless of how small, requires the cooperation of many different people. In a normal functioning company things mostly work because these habits of cooperation grew up in good times, working culture & processes adapted themselves to the activities that actually made the company money, and so when people just do their jobs good things basically result. But as the company grows and ages, it ossifies. Over time they want to do things like introduce a new jetliner, but find that the right combination of people with the right skillsets to do things like make engine nacelles that don't explode no longer exist.
This is why advice for turnaround CEOs is "get the wrong people off the bus and the right people on the bus". And they frequently hire outsiders, or folks from much earlier in the company's history. Their first task is to stabilize finances.
Their next task is to identify the parts of the company that are still functional, then double down on them (often made harder because these folks were often laid off as part of stabilizing finances). Their next task is to sell off or lay off all the folks that are embedded in organizations that are no longer serving the company's purposes. Remember that there are > 100K employees, and you're building a product of exceptional engineering complexity, and that nobody knows everything the company is doing. It's pretty hard to have enough visibility into the company's product, engineering, supplier relationships, employee base, finances, etc. to do this correctly.