> The fact that nobody dies or a regulatory body doesn't fine you straight away, or as you put it, if it's "arbitrary" doesn't mean much. The industry your whole company is in, at some point was also an arbitrary choice by whoever started it. We're humans, pretty much everything we decide to do is arbitrary.
The problem is when you treat deadlines as something very important and absolutely essential to meet, especially when the dates have just been made up, without even having the full picture of what must be developed, way back.
That's how you get crunching and people having to sleep in the office. That's how you get working until 1 AM just to ship something so the system can go into prod on this made up arbitrary date. People who do this sacrifice their own wellbeing and those who don't no longer seem like team players, leading to a culture that's unhealthy or toxic.
This is especially noticeable in the video game industry, where it's become a widespread problem - even by outsourcing to lower paid developers and getting a bigger workforce as the result, the deadlines for game releases are still unreasonable and you ship buggy games (e.g. Cyberpunk 2077) on the backs of delusional young people who work too much and burn themselves out.