They are comparable in how they work technically and what they do with your data, but this is less true of "which geopolitical overlord are you supporting". I edited my post from "equally wrong when Facebook does it" to "also wrong when Facebook does it" to clarify this. To "see ads targeting you" Facebook has to steal as much of your personal data as is technically possible, map out all your social relationships, and then sell it to hundreds of companies all over the world. In any case, the path from watching Tiktoks to supporting concentration camps is long and thin. Most people are not thinking about this and are just using Tiktok because they like it better than anything else.

in that case, using Facebook means you’re helping perpetuate white supremacy through the mass incarceration of Black Americans

How exactly does using TikTok help China silence millions of camped Uyghurs? If we all switched to Facebook would their voices be heard?