In an ideal world, yes, but it can also cause businesses to spend _more_ on pointless things like redesigning their ads, buying more ads for other keywords, etc. Then there is the fact of new businesses popping up as other businesses cease to exist. Information asymmetry ensures that not everyone knows about click-fraud, whether it is currently affecting them, how to avoid it, etc. The real world is too messy.
The fraud mechanism is clicks on Google search ads which causes general distrust in advertising and so it is in both Google and advertiser's interests to block these clicks.