It is the natural result of an industry where:

- There are low barriers to entry (education is not required, profession licences is not a thing, etc.)

- A strong culture of "job hopping" has emerged, which means companies are continuously interviewing candidates, and candidates are continuously looking for jobs.

- A big willingness to sacrifice the false positives, for the sake of keeping out the false negatives. Basically companies will increase the threshold/bar to keep out the "fakers" and bad hires, even if it means rejecting legitimate hires. The mantra that it is very expensive to hire the wrong people rings throughout the industry, and has for the past decades.

- Candidates are willing to play the game. Some people are willing to grind leetcode questions for months, years, if it means they get a shot at big tech companies. Smaller companies cargo cult.