Most consumers can't stand pop-up ads or ads that float across their screen, myself included. It creates a bad user experience and resentment toward the advertiser. People go out of their way to avoid these types of ads, so why use them I the first place? It's also
"pushy," borrowing sales tactics from broadcasting, while the internet is all about "pull" and targeting.
This is probably one of the reasons why Google Ads have done so well.