I agree it's a bit perverse, but the problem predates Google. People do the real world equivalent all the time. When there are big conferences for specific companies, rivals buy up local ad space on billboards and subways.

That has caused some companies hosting conferences to pay for some of those ad spaces in advance.

Ads on billboards and subways actually bother me far more than search ads.

It's visual and cognitive pollution on public space that I've never consented to - I find it viscerally offensive.

We don't accept billboards on hiking trails, or in elementary classrooms, or in courtrooms (as far as I'm aware, though I wouldn't be surprised if someone turns up a real-life grotesque examples) - we shouldn't accept them in other public spaces either.