Or more likely, it's just a process that was born out of necessity due to them getting more and more applicants for a limited handful of positions. How else could any company handle that situation other than making their process more and more selective?

And it would seem self-evident to me that not all of their 100-250 employees were hired at that 3/1000 rate, as number of applicants will grow over time due to increased brand recognition, increased spending on sourcing/outreach, etc.