COVID-19 proved one of David Graeber's claims in his book 'Bullshit Jobs'. That is, the private sector has so many bullshit jobs (jobs which have minimal impact on real world outcomes) because, contrary to belief, profit motive is not the sole factor influencing their decisions.

A months long work-from-home order proved many private companies could effectively work-from-home for long periods of time with little impact on efficiency or profits, saving them a huge amount on office space. And the tech needed to do so has been around for years or decades.

Yet despite this, work culture dictated that any legitimate company needed an office and had to have most of its employees come into work everyday.

This work culture principle was so strong it went unquestioned even when it became redundant due to new technology.

Just like that, there work culture assumption that a full-time job should be 8 hours a day 5 days a week triggers the proliferation of bullshit jobs in the private sector. These hours were developed for factory workers to prevent overwork during the Industrial era.

In white collar/office jobs work has boom/bust periods. So offices create a make-work bureaucracy to fill those hours with most white collar employees still expected to work overtime (may or may not be paid) during the boom periods of work when they actually do become vital.

Historically, most jobs were paid by the task not the hour. Farmers worked 12-16 hours during harvesting/planting and just a few hours during the off seasons. Many jobs are still like this if we shave them down to essential work but that's unacceptable as per modern work culture.