A browser doesn't download, install and execute that file though. Check out the GIFs on their announcement[1]. They show a Google search result page linking to a URL that seemlessly takes the user to a platform specific binary.
I expect that they'll give Instant Apps higher ranking. It's what they did with Google+ profiles and AMP pages. If Google gives people better SEO by converting their pages to native apps then that's a huge carrot for businesses to move their development to this platform. And the web is going to be made a second class citizen, even in the browser.
Google wins because they have companies and consumers locked into their ecosystem. Apple and Microsoft lose because they can't run Instant Apps like they can with web apps. Consumers lose because they're locked into Android.
If Microsoft were doing this it would be viewed with skepticism and labeled "Embrace, extend, extinguish". I think that eventually we're going to realize that having a single company control the world's most popular OS, most popular browser and most popular entry point to the web is a not a good place to be in.
1. http://android-developers.blogspot.com/2016/05/android-insta...