If only one of them earns a salary, and it is agreed upon by both, why is it unfair? That’s a perfectly valid choice - not everyone is a careerist and if one salary is enough for the family it is a really healthy choice. This “life is about work mentality” is honestly, harmful.
Doing chores at home is no less hard than working at office, and much more thankless activity. Both me and my wife much prefer to do anything else than domestic labor, including actual work. So, it is quite unfair to ask only one of us to do all this.
The primary thing is who is at home with the kids, chores can be split in a more balanced way.
Kids are at school on weekdays. And I work from home particularly because I don’t want to have less time with kids.
IIRC this appears to still be the standard in e.g. Switzerland. Expensive (2-3k CHF per month) daycare only incentives this further.
I live in Switzerland. It is “standard” in some of the conservative German-speaking cantons (though things are changing even there), but not here in Geneva.
Domestic labor is hard and thankless. It is very unfair to pile it up on a single person (in nearly every case a woman). Both spouses need to do their fair share.