Honestly I just like the idea of it because if someone decides they really want to grind for a bit they can now take up a second up to full time job without worrying about most of the shit employers will give you for that.
What I think should be the standard is a “full time” job being 18 hours in a week of work time, including commuting, with any time above every additional multiple of 18 immediately paying out as 2.5x the pay that’s been earned so far. Doesn’t just give people their free time back in spades, it also significantly discourages extorting workers for overtime instead of staffing adequately because now it’s literally more expensive to pay out any overtime at all than it would have been to just hire the additional worker at equal pay, and that effect ramps up exponentially too, by the time you’re at the soul grind of a 40 hour week you’ve already tapped your employer so hard it would have been cheaper to hire 5 additional workers than it was to make you work that 40 hour week.