Research that claims a single person making $66K is upper income calls into question if they understand how wealth works or if their just torturing data to support their hypothesis.
Granted if you looked at a more raw measure the problem likely, IMHO, be actually worse.
As for the equality article, trust and expertise isn’t established quickly. It too has a flaw in that none have expertise. One performs better, how much better and how noticeably better isn’t disclosed.