Vertical integration is superior if you can pull it off. Big fucking "if". There's a reason why automakers don't usually do it.
The name of the reason is: corporate rot. They don't have the organizational backbone that wouldn't let their "in-house manufacturing" rot away into inefficiency and waste.
Not that it has much to do with why automation fails to penetrate certain tasks. The reason why "long tail" tasks are often beyond automation is: piss poor ROI, calculated correctly.
You go out of your way to automate a certain process with traditional robotics, and it'll probably pay off in 15 years. The chassis this applies to is going to be in manufacturing for 10 years. At least half the systems work you've done there would have to be redone for the next chassis. Fun.
The bean counters counted their beans, and found out that using traditional robotics there is a losing game. Thus the search for better options. And the humans performing the tasks in the meanwhile.
> Not that it has much to do with why automation fails to penetrate certain tasks. The reason why "long tail" tasks are often beyond automation is: piss poor ROI, calculated correctly.
I actually don't think any of the big automakers have ever really, in-depth considered the ROI of "traditional" assembly automation (i.e. anything SoTA pre-2020), with experts in all parts of the process in same room. It's easy to assume that these companies must make careful measured decisions based on evidence, but in practice big decisions are made by small groups within the C-suite, often pretty divorced from the reality on the ground.
For example, many of the big asian automakers seem to have completely ignored the well-understood effects of their demographic crises (i.e. significantly aging population) on the future of their workforce (i.e. they are having trouble retaining and hiring new workers as the older generation retires) and this totally changes the economics of automation! Now they are all having to play catch-up, having realized that they must automate, at whatever the cost, because the issue is not "robots must be cheaper than human labor" it is "we might not be able to afford human labor at all".