Once upon a time, a hiring committee was presented some feedbacks and had to come to a yes/no decision for some candidates. All them were rejected. It turned out that the feedbacks were of the hiring committee's members, from when they got hired.

I've heard this before, is there a source for this? It has all the hallmarks of an urban legend...

I don't have the source anymore but it was an article where they spoke to someone at Google HR who mentioned that a particular team was difficult to approve anyone or hiring. To prove their point, they anonymized the team's own resume and asked them to rate them.

I saw a lecture (about tech interviews) by a former Google engineer who at the time was working at Etsy. He mentioned that the experiment was performed on him and his team. The hiring committe he was a part of had acquired a reputation of being particularly difficult to please. They ended up rejecting all of their own hiring packets. I was skeptical when I heard the story. Google must do a fantastic job anonymizing the hiring packets that get reviewed, or maybe they had been at Google for a long enough time that they forgot their own process and didn't clue in. However, this engineer did mention it so it doesn't seem to be an urban legend to me. With some clever searching I'm sure you can find the video.

This is good if you assume that there's a desire to improve the quality bar over time.

You are making several assumptions:

1. That we can clearly and precisely define intelligence 2. That successful interviewing correlates with intelligence 3. That hiring people who can clear this gauntlet will generate more value for the company in the form of better products 4. That there is only one "bar" for quality

As far as I am aware, current research indicates intelligence is multi-variable and by extension there are multiple "bars" for quality one could measure. It also seems likely a team will be more successful if it includes people who are capable across multiple dimensions.

We're still in the very early days of Software Engineering. Why do we insist that the Landscape Architect must be familiar with the intricate details of HVAC Engineering?

Maybe they saw a bunch of people with outdated skills?

Source?

It was in this video but don't remember exactly when. https://youtu.be/r8RxkpUvxK0

Direct Link: https://youtu.be/r8RxkpUvxK0?t=530

Yup, this is the video!! Not an urban legend.