It's not that it's appealing. For example, I wanted to learn how to bend notes on harmonica, but it wasn't working. That's not something you can really understand without video, yet most tutorials are 5-15 minutes long and only show the actual technique at some random point in ~30 seconds (just search 'how to bend on harmonica' and see). So I take the transcript t check whether it's a method I've already tried or something new worth watching, and I also get an extra explainer of the technique in text.

Also, with videos like "what X said about situation Y in discourse Z". Sometimes you're just curious, and you can't realistically extract that efficiently from a full one-hour speech on a geolocked, untranscribed mass-media website, so it's easier to summarize the transcript of the 12 min video directly.

As for why everything is 12 minutes long, it's most likely because content creation isn't optimized to teach you anything or be useful, it's optimized to maximize watch time so platforms can serve more ads to you. The pattern is: I got you intrigued in something; you want the answer? pay me your time.