No, the company that I work for isn't Netflix, but it still has tons of customers. One of our services regularly pushes past 100k rps, and knowing much of what is covered in this guide has been incredibly helpful over my career.
When I interview people, I put as much if not more focus on being able to come up with a sane design as I do coding. Especially for a senior engineer.
No I think most people end up hiring those who have experience creating big complicated systems but haven't stuck around long enough for their chickens to come home to roost.
Of course, averages (even if true) are like stereotypes.
It would be interesting to see the tenure data on the experts (consultants/implementers) of large-scale systems, other than at the iconic ones (e.g. Google, Netflix).
We don't even know if the tenure is shorter than average.
Regardless, neither the primary motivation for a short tenure, nor even any average would be particularly meaningful with regard to what I believe to be ris's implied accusation:
Absent at least one tenure long enough to see through the consequences of the creation of the large-scale system, such a creator cannot be truly considered experienced with large-scale systems, no matter how many such creations are on the resume (even though the market values/hires the latter).
Few companies will take a product that actually needs large scale systems and hire someone that has no prior experience.
If you want to actually build large scale systems, you have to start somewhere.
Even if you just want to be an entry-level person on a team that builds large scale systems to learn by experience, they are likely going to ask you questions about that topic.
You may not need that many people to build large scale systems, but you still need a pathway as people leave that particular niche.