Without saying that white-owned businesses have it easy (no one has it easy these days), I believe that black-owned businesses face additional, unique challenges that white-owned businesses don’t. Some of those challenges are new (eg communities of color being disproportionately impacted by COVID-19) and others have been around for much longer (ranging from black communities being historically disenfranchised to the the mental overhead of code switching when talking to the majority of the country). Taken as a whole, I feel they contribute to a reality where owning a business is harder for a person of color than a white person.
That appeals to my sense of fairness in business: someone shouldn’t have to work 10%, 20%, or 100% harder to achieve the same outcomes. I feel ill-equipped to address this unfairness systemically (volunteering my time to teach code is the only example I can think of at the moment) but letting the reality of a black-owned business’s challenges factor into my purchasing decisions feels like a valid way to tip the scales back a bit closer to equilibrium.