Look Out, Amazon, Here Comes Google

I remember years ago hearing someone describe Google's biggest rival not as another search engine, but Amazon – people "view Google as a tool to research products, while Amazon is the place they go to buy". While it seems likely that Google's Shopping Actions programme will drive business, I do not see how this will break Amazon's stranglehold on online ordering, and especially not when Google's apparent long-term target here is to have people order through a voice UI, potentially having never seen the product. I trust Amazon to fix it when things go wrong. If i use this service, who do i go to? Google? The merchant? No-one?
If you look beyond other major online competitors, such as Walmart or Target, who can compete against Amazon? The answer may be … Google.