> It's shocking to me that, sometime in the last 10 years, everyone forgot that adblocking's primary argument is security.

I’m not sure about that. I suspect people don’t like how intrusive ads are. Especially in videos.

The security issue strikes me as a post Adblock rationalisation. People know how the sites they visit are funded and need some way to justify cutting that off.

The number who understand the security implications is going to be very small.

No, surprisingly people don't actually know or care how things are funded. And that's rational for them and how markets are designed to work.

The reason why I block ads is due to security. Can't be that small of a number

Links that take you to a malicious site are not the only security reason. Ads are often used as vehicles for malicious payloads, some execute when you click on them and some are 0-click.