Keep in mind the typical office commute can be very long. Let’s say 1.5 hours each day (45 minutes there, 45 minutes back.)
8.5 hour day (unpaid 30 min lunch) + 1.5 hour commute = 10 hours from leaving home until arriving home. 5 days a week = 50 hours total for work in a 5 day work week.
10.5 hour day (unpaid 30 minute lunch) + 1.5 hour commute = 12 hours from leaving home until arriving home. 4 days a week = 48 hours total for work in a 4 day work week.
You work less. Odds are with a longer shift you also avoid rush hour on one side of it, so the 10 hour work week loses another hour or two. It’s a BIG win. You get an extra 10 hours of fully conscious time on an extra day of the week which is HUGE for personal hobbies, enjoyment, family time - you name it. For me approaching 40, getting home from work I have almost no energy for personal activities after chores each day. Add on children and you get even less time aside from grinding.
Good news is that the 5 day work week will NEVER go away, so you will always have the choice of working five days and only getting two days off while your buddies take the extra day each week :)