I think it's easy to get bogged down in the financial considerations of wealth without taking stock of intangible assets. I'd mention those, too.
As a SAHM, I get to experience all of my son's milestones first-hand. I'm there to shape his character, support him, know him intimately, and enjoy little moments that will never repeat themselves, which would go unnoticed by someone else. That's my treasure, and I have a huge stockpile. Even better, this treasure exhibits increasing marginal utility! (I jest, but almost not quite.)I wouldn't trade the utility DS and I derive from my being at home for many multiples of my opportunity cost, which itself is high. Isn't that a flavour of being rich?
The loss of my income was a significant hit to us financially, but it was a conscious choice and we live comfortably on my husband's professional income. We don't own a car, we don't take vacations, and we live in a small urban loft instead of a large single family home. Instead, we invest heavily in human capital--our own and DS'--and spend a LOT of time together making memories because those are our priorities.
We are human capital and relationship rich. I wouldn't have it any other way but, had DH and I not been high income earners independently, our chosen lifestyle would have been infeasible in our high cost of living city and given our student debts.
We aren't in the 1%, where we'd be if I was in the labour market, but then again I value my son more than a Maserati or a beach house. So am I richer than the 1% because my psychic consumption set expands as compared to my working consumption set, even though I'm well below that percentile financially? I'd say absolutely. Your utility curve might differ.