It didn't always use to be that way, and it doesn't have to. That we have physical needs is a fact. That we have alienated work from life, or family, or expressing ourselves is not. That work created an absentee father is not in the laws of physics, obviously, but that it's hard to perceive it as anything else is what OP pointed out, and that's something worth paying attention to.
The idea that you have to 'move work around' (kind of sounds like moving garbage around) wouldn't make sense to a person who is able to express themselves in their work. Ask a craftsman for example, an artist, or someone on a family farm.
The fact that people are detached from their work, that they're objects of their work, that their work dehumanizes them in extreme cases, that is a result of a particular mode of production we are living under. Someone for whom their work is an extension of their life, who are not detached from the products of their work, and for whom work strengthens their social relations, there is no work-life balance, because there is no work-life conflict.
When I go over to the printmaking studio, I recognize that in principle someone else might be able to grind the limestone slabs I intend to use for printing, maintain the printing press, clean up the ink, or perform any number of tasks incidental to the expressive portion.
I am just as sure that anyone on a family farm knows they can, in principle, get someone else in the family to do work, and that hired hands exist, and can take care of many tasks or unpleasant chores. They may prefer to do the work themselves, so that they get better results, or have more control or feel useful, or because they have a duty to contribute productively.
In every job that must be done, there is an element of fun. It is essentially never entirely fun.