I don't think anything in the OP is true. I know poor atheists, Black atheists, atheists who lack any education beyond high school. I know working class atheists, young and old atheists and plenty of female atheists, including a happily married Lesbian couple. None of them are wealthy. Most of the atheists I know are happily married, although one is struggling financially after being divorced a few years ago.
There is a small town about 30 miles away that has a more organized, more active atheist groups and they are more affluent than my local group. I don't know if any of them would be considered wealthy, since wealthy hasn't been defined. I've never met a wealthy atheist when we used to attend the Atlanta Freethought Organization. Some were obviously struggling to get by. Most were middle class. Only a few had advanced college degrees and many had only a high school education. I met a few of the Black Nonbelievers of Atlanta and they weren't poor and many had college degrees. I have no idea if any were wealthy. The ones I met were all females.
Most of the atheists I know or have known identify as Humanists, which is a very idealistic philosophy, but much better than Christianity when it comes to moral values, including the acceptance, support of both gay and transgender people. Very liberal non Biblical literalists Christians hold similar values, but they are pretty rare where I live. I've met atheists who were in the closet but were glad to open up to me, when I told them I'm an atheist. One of my local atheist friend had told me that she rarely lets anyone know she's an atheist due to the negative reaction she receives. She isn't what I'd call wealthy, but she and her Christian husband are both retired GBI agents so they receive both a generous pension along with SS. How much money or income must a person have to be considered wealthy? Some of my atheist friends have struggled to survive financially and at least in the past received support from social programs like SNAP.
Growing up, I knew quite a few wealthy Christians as the evangelical church I was forced to attend was a rather wealthy one, but none of the money went to charity. The pastor made a rather large salary and he lived in one of the wealthiest towns in NJ. There were lots of members of that church who had college degrees, more so than the atheists I've met in person. I don't like stereotypes about any group, including atheists or Christians for that matter. Some people are obsessed with money, but most of us simply want a decent home, food, transportation and things like that. The exceptions are people like my brother in law who has a doctorate degree in dentistry, and who considers himself a Catholic. He has always been obsessed with money, brags about how many millions he has etc. I guess it will be harder for him to enter heaven than it is for a camel to get through the eye of a needle.
Oh, and I don't mean this as virtue signaling, but if people like me are so materialistic, why did I choose a career in nursing, very stressful, shitty pay when I was still working, considering the difficulty and educational requirements, but also very emotionally rewarding to be able to go into the homes of all kinds of people caring for them and advocating for them. Sometimes they lived in high crime neighborhoods, and we home health nurses had to be careful how and when we made those visits. I once took a young medical resident with me and he told me that my work was more like missionary work and he didn't know how I did it. I don't know how either, now that I'm old and would be afraid of some of the things I faced during my younger days. I also enjoyed working in long term care and being a friend as well as a nurse to people who were often very religious, but that didn't stop me from caring about them. I've met other atheist nurses and we used to have one here who worked in hospice. So, enough of the stereotypes about atheists. We are unique just like religious people are in their own ways. Still, regardless of what one believes, it's a joy to be able to help others, imo and as long as I have enough money to be comfortable and even be able to afford to help out a few friends now and then, I can't complain. I don't even understand greed, certainly the deadliest "sin", which is currently destroying a lot of things in the US.
And, btw, the few extremely wealthy atheists/agnostics, do give away most of their wealth. Warren Buffet is an example. You may not think much of him, but he has given away most of his money and is leaving most of his wealth to charity after he dies. Most church people give to their churches and other religious causes. I doubt many give to secular charities. Enough!