They call it “dark traffic” - ads that are not seen by tech-savvy users who have excellent ad blockers.
Not surprised that its growing. The web is unusable without an ad blocker and its only getting worse, and will continue to get worse every month.
The hilarious thing is if you turn off your adblocker (or use a service/device that doesn’t support it) and pay attention to what is being advertised to you, a lot of it is wildly irrelevant. They’d probably have better targeting by following the old TV Ad model than whatever the heck is happening with targeted web ads nowadays. My wife watches a lot of livestreams on twitch and any ads that aren’t for a game just consistently seem to be wildly irrelevant despite being “targeted” or it’s even worse when she’s listening to Spotify and the ads are so consistently for products or services we would never have a desire to use