Even if I could afford to support her, there are still costs.
I remember back from my woman's studies classes that back in the 50s and 60s one of the worst things that a woman could do for her mental health was get married (and one of the best things a man could do was to get married). Unfortunately its not really clear why this happened. Was it being trapped at home away from adult company, was it lack of decision making authority, was it housework was dull?
Done properly a home maker does improve the economic standing of a household, by both making it possible for the higher paid person to spend less time having to deal with chores and more time on career advancement, as well as options for reducing costs by producing goods in house (like cooking or making stuff).
Also paying someone else to do your household chores can get pretty pricey, and if you have a child, paid child care can be expensive enough that if you make less than $30,000/yr its probably cheaper being a stay at home parent).
Also when I was working from home I found that it could be really isolating.
However there's also power issues from one partner being dependent on the other.
It seems complicated, and I wish she could have a job that was more like 10 minutes away.