The discussion here isn't about code. It's about quality of engineers hired. If their software and product quality is steadily declining then that says something about their team. Perhaps they are incredible coders but don't have good business skills or "customer obsession".
> If their software and product quality is steadily declining then that says something about their team.
My understanding is that Google internal politics are completely dominated by their promotion process [1]. I view the outcome of google products not as the result of poor hires, but the inevitable consequence of the organization's incentive structure. If pay (doubling or tripling) is dependent on launching new stuff, your best people will ship new stuff! If pay does not go up for maintaining old stuff, it will not be maintained. If pay does not go up for improving old products, old products will not be fixed. It doesn't matter which people you plug into that system, you will always get the same results.
Why do you assume that poor products are poor products chiefly because of code?