I don't know how prevalent this experience is, but on average when I have gone to local black restaurants (Los Angeles), it's not uncommon to experience all or one of the following:
*Minimum of $20 for a meal (this is pre inflation as well, for as long as I can remember)
*Employees seem annoyed I even walked in.
*Wait time is about 30mins to an hour.
*The food is not good.
This isn't to say you can't get this experience from non- black restaurants. But on average, from my own experiences, Black businesses can have terrible customer service. Which doesn't make any sense to me because if I go anywhere not black owned that has black employees, the customer service is great. I always feel like black people give employers the best bang for their buck if the pay is decent. We are amazing at making people feel welcomed...except if we own the place. Idk.