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.