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.
Unless the lovely javascript detects that you’re trying to close the tab and hijacks that to ask you if you are sure you want to
forcefully tell them to fuck off and dieleave the page. It’s only one extra click, sure, but I remember some from the old days that wouldn’t let you close shit. Ugh, thank god for better modern standards and adblockers.