There's no straight answer to your question, OP. There are so many variables.
Of the SAHM's I know , it is either a high-earning DP, or less likely, inheritance. I live in a relatively expensive area.
Of the WOHM's, it's usually maintaining a professional career where it pays enough to finance childcare. or escaping domestic drudgery
I work p/t & think it gives me the best of both worlds. However, for my. 1st 6 months back at work, the childcare cost for 2 children was an absolute killer financially, even on 2 professional salaries. It would not have been sustainable long- term, but nor would SAHP . Thankfully DS started school & it is now easier.
We don't have holidays abroad ( holiday this year was 4 nights paid by inlaws), went down to 1 car , rarely have meals out or takeaways. And that's with both of us working
I don't think I could face a life of no haircuts, no car, EBay clothes , etc.
But each to their own.