The idea that "whiteboards or PowerPoint slides" should be singled out as a particularly persuasive dark arts technology ... sounds ridiculous to me. I can't recall the last time a politician or climate dismissive tried to convince me with either of these, but I did see a professionally done anti-vax video on Rumble once. Indeed, things like bar charts, high-quality animations, repetitive ads with slogans, or certain subreddits (in which you would quickly be banned for presenting certain facts) all come to mind before powerpoints.
I'm not sure "dark arts technology" even belongs on the tag page for "dark arts".
Dark Arts is a colloquial term for techniques or methods which involve deception and/or manipulation of others or oneself into believing things for bad, i.e., non-truth-seeking reasons. These techniques may prey on human cognitive biases.