Eh, not really a convincing explanation. Many groups have come to the US with essentially no wealth either, and have managed to accumulate quite a bit of it.
Yes, but those groups came of their own free will, were not enslaved or treated like property, forbidden from reading or attending any educational establishment, forbidden to vote or register to vote--on pain of death--IN MY LIFETIME FFS!!!! And I'm not old enough to retire! Refused loans or admissions to schools with white children, refused attendance in movie theaters with whites, refused the privilege of using the same water fountains, refused treatment at white hospitals, or a host of other laws and social conventions developed and put into place expressly to keep them from being able to move up from sharecropper or housemaid.
Walking down the street, if you encounter someone whose grandparents were Irish, or Russian or German, etc. you will probably not necessarily know where their grandparents came from and will probably not think twice about whether they deserve the clothes on their backs, the jobs or places in universities, or housing. The assumption is always that of course, they earned it or, perhaps their daddies were rich and passed along some of that to future generations. You don't think: I'll bet her great great was an indentured servant. Heck, my grandpa farmed with a mule and plow and was grateful to upgrade to a horse and later an actual tractor. My father's first job on the farm was sitting on the plow to hold it deep in the earth and hopping off to move rocks out of the way. Not a heck of a lot different than how a lot of rural black families lived in the 30's. But I can walk into any department store or restaurant or government office and nobody ever--EVER--looks at me like maybe I don't belong. Like maybe I'm using a stolen credit card, or got my clothes from the Goodwill (although certainly I have gotten clothes from the Goodwill) or gives me any sidelong look while they check to see if I'm using a SNAP card in the grocery line. I've never been redlined (in the bad way) when house hunting or applying for a mortgage. My kids did not get followed around stores the way their (better dressed) black friends did. I worried about my kids when they were teenagers but I never worried that they would be shot by the police if they were pulled over.
My husband is a university professor but he has never been arrested in his own home because someone thought he didn't belong there. No one has taken me for a maid. Ever.
So STFU.