I wouldn't attribute a rise in the use of ad blockers to Google or Facebook. It's more of a reaction to intrusive ads, the sort where a video expands to cover

I wouldn't attribute a rise in the use of ad blockers to Google or Facebook. It's more of a reaction to intrusive ads, the sort where a video expands to cover the content you're trying to view. Most people (that is, average users, rather than technologically-inclined ones) don't care that much about tracking. As far as Google and Facebook pushing other advertising networks out of business, it's not that they're so effective that no other strategy is possible. It's more that they're effective enough, and so cheap that other networks can't compete.