It's hard to write about the broader context with any expertise in a blog post written from personal experience.
My own thinking is that the big competitive advantage that big tech firms have over small ones is the power to mobilize very large numbers of developers onto a project.
Large projects that don't depend on a small core group of irreplaceable competent individuals are more repeatable for a business. So it makes sense to focus on making the repeatable processes more likely to succeed than simply hope that you happen to have the right team assembled for the job.
Assuming that any of your engineers are above or below average hurts the ability for the business to plan.
True but this isn’t something big tech innovated. This is exactly how most large organizations work. For example, and specifically in the military, servicemembers are fungible and they are rotated every 2 years. The military even encourages attrition at certain ranks and points in people’s career.
big tech firms advantage is privileged access to public money, without focus on quality or cost. Good products start small.