Interestingly, the Google download page is copyright by Google.

Microsoft changing that page for their profit is 100% NOT fair use. Google should simply sue them for all those counts of willful copyright infringement at $180k each.

I don’t believe browser rendering is considered an act of publishing or distributing, is it? Either by the browser developer or by the computer user? I don’t see a mechanism of infringement. It would be different if Microsoft hosted a fake download page for Chrome on its server.

MS had to add content to the page then render that new content. That would count as a derivative work which would be covered by copyright.

Normally, when a user does this themselves, it isn't for commercial purposes which puts it in a different category (plus, the most popular modification involves stuff from loading onto a device rather than modifying the stuff that was loaded). This is far different in intent.

By this logic, no one would be able to serve banner ads on top of copywritten content.

Plenty of existing and historical malware browsers and plugins have injected ads.

Furthermore, because it's a full page width banner, it's not entirely clear whether Edge is rending something next to Google's page (i.e. in MS' browser) or in Google's page (i.e. commingled with their content).

I think your logic is flawed. Banner ads are explicitly permitted by the web site operator (they get paid for them after all). Plugins aren't permitted by the web site operator, however they are permitted by the user, who has to explicitly approve installation of the plugin. Same with malware browsers: the users chose those. Of course, the users were ignorant and clicked on something they shouldn't have, but still it's ultimately their own fault: they opted in.

It's different with Microsoft: MS never asked for users' permission to change content, nor did users ever expect it.

How do you get from 'users opted into malware browsers/plugins' to 'users didn't opt-in to Edge/Windows'?

Edge comes with Windows, and users pick Windows because it's the default choice and basically a monopoly for PC operating systems.

I don't think a browser render counts as creating potentially infringing content. I'm at a loss to explain why but I think it's the ephemerality of a browser render and the lack of a distribution method. Where are you getting the idea that infringement is possible at all by the browser itself, regardless of fair use laws?

>I don’t believe browser rendering is considered an act of publishing or distributing, is it?

If it were, I think this could cause big legal problems for ad-blockers. Of course, one big difference is that ad-blockers are usually installed by the user, and so explicitly have the user's permission to change browser rendering, whereas MS changing the rendering of competitor's web pages is not expected by the user nor were they given any permission for this.

Would that effectively kill adblockers legally, at least those which do cosmetic changes?

it doesnt change it server-side, and doesnt serve a different website.

it injects html.

Standing in front of the TV to get your Mom's attention isn't copyright infringement.