I'm not disagreeing with that specific point. Just making a corollary that by doesn't necessarily identify what it is in all contexts, as it's more ambiguous depending on where it's used. For a restaurant, it's fairly obvious because we have prior assumptions about the service. It it was laundry, the assumption might just be it was advertising itself as a black owned business. For a streaming service? Probably more on the side of how a restaurant is seen, but why even court that confusion? Most restaurants would avoid it as well, and call themselves Soul Food or some other moniker that clearly communicates what it serves as opposed to who runs it.

"Restaurant by Black People" might communicate something about the restaurant enough to most people, but it's also just a poor choice of description all around. Netflix by Black People is similarly a poor description, IMO.