The issue is, it's faster to build a feature yourself than to coach a new hire to build it.

So if an org doesn't value mentoring and growing engineering talent, you'll end up with a few engineers doing most of the work and an org that magically can't scale.

Then you'll see the hiring side buying in on the cargo cult and trying to hire seniors with resumes matching their existing devs, then whining they can't hire them for cheap. At this point the business velocity has reached it's top speed.