I have seen what old age and infirmity looks like when you’re poor and it isn’t always that pretty. We all get old and fall apart eventually, but the ability to choose your situation (and take care of yourself so that you make it farther into old age with good health) matters a whole lot. This doesn’t make everyone implicitly happy, but it gives you a better chance.

I didn’t include poor in my comment. Poor people (lower and lower middle) seem to have a much lower quality of life and general happiness vs middle middle and upper middle.

I think middle class just doesn't exist anymore,or won't exist soon enough. Concentration of wealth killed it. Hence less children.