I ended up googling cancel prime membership, and that led me to a page with a cancel button.

I'd say we crossed the Rubicon on this front decades ago, when in-person, at the theater, movies started showing actual ads and not just trailers before the movie you just paid for (and it was at the same price, of course).

I remember the first time I experienced this in a theater. My GF was like "....the hell?" and people were fucking booing the ads. But it didn't matter enough - the ads are still here.

And yeah, it still annoys me.

That's the great part, you can't cancel.