DNS-over-HTTPS: iceberg, tip of
DoH was first because it was easiest to justify. "Think of the poor children in oppressed regimes!" they said, but we know it's low hanging fruit. It's an easy sell AND DNS-level is the easiest way to block tons and tons of crappy flashing ads.
I used to only manually block the worst ads, but it turns out 1) all ads come from the same handful of servers, and 2) there are very, very few ads that aren't "worst." So, starting with a fresh ABL install, I find I'm blocking basically 100% of ad content by the end of the week anyway. I genuinely tried to leave "nonintrusive and interesting" ads in but there simply are none.