In domains in which the underlying domain is complex, with an irreducible informational complexity, as well as rich and frequently highly significant interactions, there's a frequent emergence of faddish, or ritual-driven, behaviours. Both seek to reduce risks and accountability, as well as to increase credible signalling of traits.
Both sides of the technical recruiting transaction (job-seeking and recruiting) exhibit these behaviours and tendencies (what to wear, how to format resumes, presentation, side projects, for seekers, interviewing, tests and screens, and other filtering practices for hiring teams).
The consequence is a tremendous amount of friction, inefficiency, and fear-driven lore. Some years ago a senior Google staffer commented that they'd found a guaranteed hiring heuristic: "No". That is, reject all candidates.
My response was that if this was serious (and it was at least partially), that this was a profound sign of weakness within Google: an inability to seek out and onboard talent successfully.
There are other possibilities.
It could be that the notion of private firms hiring highly-skilled talent is inherently flawed.
I've speculated that one of the justifications for the ancient Egyptians to build pyramids was as a combination of a skills-development, skills-retention, skills-demonstration, and brain-drain-mitigation programme. From what I've read there's at least some independent informed speculation along similar lines.
One of the functions of writing a book, a notoriously unremunerative practice, is as a credible signalling of skill and ability. (And of book-writing capabilities, for what that's worth.) Books are very fat sales brochures.
In a tech world in which typical tenures are measured in months or single-digit years (2--3 years being typical from what I understand), and correlations between any hiring practices and actual performance ... at best weak, there's an inherent issue.
There's also the question of equitability of a process in which employers have vastly greater access to information on individual prospects than prospects do on companies or hiring managers / management teams. George Akerlof's "Market for Lemons" suggests that more information makes markets more efficient, though my fear is that highly asymmetric information access further tilts the employment market in the hiring firms' favour.
https://www.jstor.org/stable/1879431
http://libgen.rs/scimag/10.2307%2F1879431
Some of my earlier fad/information theoretic musing here:
https://old.reddit.com/r/dredmorbius/comments/62uroa/clothin...