I experience this irritating phenomenon all of the time. I was a corporate executive, and I can answer a question a Black person asks, and my answer isn't legitimate until someone White validates it for them. And they will casually say that they checked with Joe Eddie White Boy or Becky Blue Eyes, and low and behold I was right. And yes, it's the same with Black businesses.
To a lot of Black people the prices are too high, they're rude, it's too far to travel to their location, why not cut a brotha' or a sista' a break, but would sell a kidney to pay for some Kylie Jenner make-up, Kim Kardashian merch, to eat at a fancy White owned restaurant or diner, buy Chanel, Louis Vuitton and iPhones....no questions asked and no complaints made. Most of our wounds are definitely self-inflicted and we don't really seem to be able to heal.
During segregation, Black people had their own cottage industries and eco-system, recirculating Black dollars within the Black community, due in part to the Green Book and out of necessity. But the second segregation ended, Blacks threw their own people under the bus, gave their hard-earned dollars willingly and freely to White businesses almost exclusively (though those in charge still didn't like them, but would still take their money) and never looked back.
I often wonder, because of a lot of what you wrote and what I've observed, was ending segregation really as good for Black people as we thought? Yes it was evil, but Black people relied on each other far more than we do now. They were focused and unified for the greater good, but starting with my generation (I'm a younger Gen-X), we flew in all different directions, with many of us actually thinking racism had magically disappeared because we were seemingly free to do what we wanted, and we weren't being hosed, lynched and beaten like the Black people in our parents and grandparents generation, and we never really came together again as a cohesive people. And here we are.