I haven't used Google's search engine in a very long time now, but don't they sort of cycle through a bunch of adverts, so even if you did refresh it might not be the same advert displayed? That's usually, how adverts work across the board, I just can't remember how Google does it. So, you could just get unlucky, and not see that advert for a while, but they're still paying for it.
Does it get replaced by another advert when it's not there?
When refreshing the ad disappears. As I say, at most I only see this once.
In that place, only this Binance ad appears, when it does not appear, the place has no advertisement.